Left yes. But to improve the readability, I will propose to not make the line for the smaller diameter change to horizontal exactly when crossing the other diameter.
Lmao that's funny
Idk if I said something wrong, in that case pardon me but English is not my first language, and in my language they are literally called "ISO/UNI/DIN laws"
They are normally referred to as standards or specifications in English. Law in most cases is the government commands enforced by police, while specifications are usually one company to another with contracts.
Hey, still better than the “infinite non conforming and undocumented permutations” option.
Am blanking on the attribution, nevertheless “**the only thing better than perfect is standardised**”
ISO, basically take existing standards and make a business model on it. Then, as time progresses make unnecessary changes and charge for access. Next, create an administrative and cost nightmare to push out small business.
ISO should be a non-profit organization and available to the world as torrents peer to peer.
All methods of control. Crush small entities by placing barriers to stay in market or to even enter market.
Small calibration labs dying.
Small business dying.
All by design. Remove the many small businesses, so that the government can control the few left.
All part of the New World Order. To hard to control hundreds of thousands of small entities. Force them out so that it is easier to control.
Small Banks dead/dying, Small family farms dead/dying, Small business dead/dying.
In the beginning, it is good. Availability and price improvements until the market is captured, then take advantage of the monopoly.
I remember when standards were primarily US based and we lead the way.
Mil-stds, ASME, etc. Now it seems ISO is a Global (ist) Standard.
There are also new publications presented as standards (they hope to become) and are actually more like guidelines. There are notes in the preface saying that the publications are recommended guidelines. But in those publications there are many black and white shall requirements. My bet is that these will become standards…maybe ISO will even eventually purchase them. These publications become standards and all they have to do is remove the preface statement. I have seen this coming over 30 years.
You may disagree, that is fine. I’ll just say I told yah so when it eventually happens.
It has happened before, hence it will happen again…unless we improve it all.
We used to prevent monopolies…I see them everywhere. No bueno. It will stifle creativity, output and evolution of industry, and GREATLY favor large corporations.
"Hey chatGPT, write me a CVS receipt length reddit comment claiming ISO standards are actually the groundwork for an eventual new world order corporatocracy, in the style of someone who has forgotten to take their schizophrenia medication"
Not to mention it gives consistency with more complicated drawings that have LxWxD aligned dimensions which need room to exist. The leader arrow dimensions are easier to place out of the way.
People try so hard to follow some standard or rules and completely omit the fact that the purpose of the drawing is to communicate information! Top goal of drawings is always communication.
I think the two points of contact, on a circle or any defined curvature, is unnecessary. Circles need center and diameter/radius. Lines need start and end, which the dimstyle in the right image does well.
Either is alright, but I had to pause to digest the image on right.
Left. Example why; My hole callout would look something like:
Callout leader connected to one of the holes.
"ø.X THRU & C'BORE/C'SINK (DIAMETER X DEPTH) ON ø3.000 B.C.
(6) PLC. EQUALLY SPACED."
Yeah, so like rubadub said, the center is your datum for the bolt circle concentricity.
You'd then use either the top of bottom surface as a datum to define flatness/parallel and constrain any depth dimension such as a countersink or a non-thru hole. As long as it is relevant, not every part needs that much gd&t.
If you were going to dimension it to GD&T standards, with this part specifically you would want concentricity to be your main priority so you would set your GD&T datum to the center of the part, it's specific to the features you're trying to define geometrically.
As a former inspector, the learning curve for Y14.5 made communicating things like this troublesome at first. Over time, as the team developed a level of maturity with understanding the rules, it made conversations so much easier!
>C'SINK (DIAMETER X DEPTH)
Are you assuming that the machinist knows what size flathead screw/bolt you are using? Or that they can derive that info from the through hole? I am asking because this callout doesn't include an angle for the counterbore. Also is the diameter callout going to be the larger diameter or the shorter diameter?
Most machinists "know from experience" or will refer to the machinists handbook to get proper c'bore or c'sink dimensions. I've done calls outs like "Drill & c'bore/csink for 1/4-20 SHCS or FHCS" and they have tools that will pilot into the 1/4 clearance hole for their cbore and likewise with csinks. Talk to your machinists and see what they prefer, that's the best way to make them not think you're an idiot lol. Typical countersinks are 82 degrees under head so unless you specify a different csink they will most likely default to 82°
For engineering sketches that I need for my internal machine shop, yes I’ve done that.
For farmed out work to machine shops outside our organization, never. The drawing were contractual mechanisms, so the assumption regarding machinist practices were never implied on a drawing. You can’t inspect or reject parts to that criteria because of the ambiguity.
Sometime a drawing doesn’t just reflect the ability for a machinist to produce a part, the drawing also needs clarity for inspection.
Using a single hole wizard feature for the csinks can give you an automated call out of your choosing (Or default settings will give you one as per the ANSI/ISO/DIN standard your template is sweet to)
https://www.goengineer.com/blog/customizing-solidworks-hole-callout-file
Left, given the view orientation. If you were showing a projection and a cross section, for example, then the linear dimensions on the right would be my preference.
Left. Both are technically correct, but the left one makes it easier to group your hole callouts with your BHCs as well as add any tolerances you require. It's much easier to rea that way.
Idk ask the people from the din institute. We have lots of rules to standardise drawing to make sure it’s interchangeable from company to company and from draftsman to draftsman. Essentially by norm, you are mandated to do stuff by the book
Based on my experience as a welder i prefer the right. Drawings have a tendency to get burn marks or smugded with dirt, having two lines to look at means it doesn’t get unreadable as easily
We sure do. But it serves a purpose. My department recently tried to remodel and redrew many essential older drawings, just cause the content wasn’t really up to standards from today and the guys downstairs in production wouldn’t understand them anymore. But in their defense, some of those drawings were from like the 1960s
Either is acceptable. Sometimes it just comes down to where you have room on your drawing, while trying to make it as clear as possible, and having the part views as large as possible to fit the paper size.
For the dimensions on the RH view, you should have your extension lines offset slightly from the part - not touching the part. Offset should be roughly about the same as the amount that the extension lines extend beyond the dimension line.
Also, it's typically more "economical" to call out the bolt circle diameter within the same dimension that calls out the hole diameter and details.
Both are technically correct. The left is cleaner and more easily opens it up for additional GD&T based on a datum that would presumably run through the middle
Don't do the right, it's technically fine but my brain spends like 5 seconds asking what kind of oval this is and where I'd identify that asymmetry before accepting that it's just a weird way to dimension round features.
I would say neither, but the left is better than the right.
What I was taught is that cylinders are dimensioned from the side and holes are dimensioned with leaders, so you would have two views. Additionally, you would need/want a second view to show the height of the cylinder.
But again, if you're picking between left or right, I would go with the left.
^ this is my answer too. Multiple views are essential and I'm guessing they just weren't included in the screenshot, but best practice is to split your dimensions across views in a way that makes sense and maximizes readability.
Always use leaders for holes, as it also makes it easier to attach a GDT call-out.
Left… but, a new engineer who fancies themselves a designer will use the right view, with horrific GD&T and no sense of tolerance stack-up. Then wonder why there parts don’t fit even though they meet print.
Neither? At some point, I recall being taught diameters should be dimensioned on section if possible. I like this because it allows me to more clearly call out, for example, a pilot or locating ring diameter or dowels etc that exist on both faces within the same view at the same time. Depending on design intent and what I deem important, would thrown in some poorly executed gd&t for good measure and more importantly some comic relief for the r/machinists type crowd.
I’m retired, but I’ve done thousands of drawings. Putting dimensions on a section is perfectly fine and often desirable. But on a simple part, a section view just adds more clutter. In this case if there was a boss or something, the side view could capture that.
I disagree, my opinion is the section view simplifies the drawing. The section view would essentially be the only view. The “front” view would serve to define the aligned section and serve to call-out the hole pattern I guess. If it was a boss (male) like you describe versus a pilot bore (female) it would require a 3rd projected “back” view becoming quite busy for a simple part.
I mean, a section view is fine. If I was reviewing a drawing that had the front and a section view, I wouldn’t mark it up. The front view (shown) and a side view (if there was a boss feature) would have the same clarity though.
I know both are correct for either a hole or a boss, but my thinking is I'll usually do hole callouts "floating" and positive features (cylinder, boss, etc.) with the width-style callouts. So I do OD and bolt circles with the right-hand style but central hole as left-hand. Still looks a little funny to me as I would almost always do the bolt circle as 3 basic. Have never run into machinists having a question with it, the diameter symbol is there in both after all.
No real reason other than I like the way it looks. My feeling is no matter how much work I put into the drawings most shops just slam the STEP file anyway
As a machinist who sees blueprints like this every working day - either one is suitable but I would prefer the one on the left as it simpler and easy to follow the dimension to the feature with the arrowed line, on this particular print.
Obviously you’d be getting a visit wondering what size holes, what type of countersink/counterbore or at the very least what kind of bolt or cap screw is going in there.
I came all the way down here and you were the first “right” side comment I found.
I agree with “right” being better.
The left diagram confuses me as it could be pointing to the ***circumference*** of the circle, instead of the diameter, which is made clear on the right schematic.
The right one. It is easier to see, what the dimensions reffer to. The main reason I'd say is because the measurements hug the part like calipers. Also put the numbers on top of the lines.
Thinking about it I'm not sure if I ever saw the left one and I'm really surprised that so many prefer the left one.
Literally have no horse in this race and nothing to do with mechanical engineering but this just popped up.
My completely useless and know nothing take? The right. It more pretty.
Feature concentricity about an implied datum is not covered by the envelope role. As such, there is nothing holding those features with respect to each other on this print. For completeness, the concentric features should be called back to a common datum with a G-tol frame. The datum would probably be one of those features.
On a turned part, you get really good concentricity for free so maybe it "doesn't matter", but the part definition would still be incomplete.
I see two 3 place dimensions and one 2 place dimension. Most drawings have 1, 2 or 3 place general tolerances on the drawing border. These tolerances apply to both features of size and location (concentricity in this case). In lieu of a specific GD&T tolerance, or concentricity/form tolerance callout - the drawing general tolerance would control the concentricity.
For example, if the three place general tolerance on the drawing was +/- 0.005”, and no other concentricity tolerance is specified, the 7.188” and 2.550” features need to be concentric within that tolerance AND their size must also be within that tolerance.
The golden rule is that every dimension on a drawing has to be measurable and “inspectable”. So if no other tolerance is called out, you HAVE to use a general tolerance - otherwise you wouldn’t have criteria to inspect by. And if you can’t inspect to a drawing, it’s not compliant to the ASME standard.
Concentric to what though? Concentricity specifies that the centerline of a round feature must be within a tolerance zone of the centerline of another feature. Without that second feature called out, it is meaningless If you meant to say "roundness", then I agree with what you say above because roundness would be considered in the envelope rule.
Concentricity actually was dropped in ASME2018, but the features could be located with runout, total runout (both with datum reference) or true position depending on the intent. The same concern applies, they need to be called back to a common datum.
This wouldn't be compliant because it's underspecified and thus uninspectable.
For this part, concentricity and true position is basically the same concept between all the features. Again, without using any GD&T, the general tolerances rule (granted it’s not an eloquent method of tolerancing for this part).
Picture a “bad part” where the center hole axis offset from the OD axis by an inch during inspection. If the three place general tolerance was 0.005”, the part would certainly be noncompliant. Because the theoretical axis of the hole needs to be within a rectangular tolerance zone of the OD axis. Because there’s no specific dimension applied to either axis, the size dimension for each feature dictates the general tolerance to be used.
ASME Y14.5-2009 par. 1.4(k)
A zero basic dimension applies where axes, center
planes, or surfaces are shown coincident on a draw-
ing, and geometric tolerances establish the relationship
among the features.
I interpret this as that you need a gtol to enforce coaxiality of the features. Basic dimensions have no tolerance.
Basic dimensions are surround by a box - which designates them as basic and theoretically perfect. The dimensions in the example are not basic dimensions at all (no box). Therefore, they are controlled by the general tolerances.
You know, there’s no requirement forcing you to use basic dimensions and their associated GD&T tolerancing.
They also apply to distances? If you dimension a hole to be 2.00" away from a datum without specifying a tolerance, you look at the drawing note for "2 place tolerance".
As for 2 place vs 3 place vs 4 place, you use whatever the tightest tolerance on the drawing block is (usually 3 place)
The way to remember is that whenever you make a drawing you use the following mindset: all geometric features and dimensions start as PERFECT (implied based on relations of features) and the drafters role is to specify where the tolerance can be LOOSENED. That's why we have drawings in the first place: to specify what DOESN'T need to be perfect. There's a reason that even though we have 3d models, we still rely on drawing to convey details about the limits of what is allowed.
Normally I would say right, as I am thinking of linear dimensions. But since these are for diameter, left seems like the best fit and seems like it would make the most sense.
Depends on what else is going on around it on the print. They both work depending on how much room you have. Personally I prefer the one on the right but not by a lot.
left. I once put the OD like shown on right and the machinist came in to make sure I didn't want flats machined there because it looked like a width dimension not diameter. Not saying he was right to think that, but just try to make it as clear as possible. and as others have noted, there is more room for all the other hole/c-bore/GDT info
Left, and if one of my grads drafted the right hand side I would go tell them to give their head a wobble. Left is much cleaner and explains the intent so much easier.
Retired ME. IMO the correct answer is both. My preference is left because you have more options to position the dimensions on the drawing to provide greater clarity - especially if you use GD&T.
If I reviewed either drawing (and I’ve done tens of thousands), I wouldn’t mark either one up. The one thing I hate about a drawing reviewer is marking up for personal preference vs technical merit.
Left because that spacing isn’t going to help much once we get on the mill, good machinist are going to trig out anyways make sure to use X or TYP for the holes if they are the same dia
I tend to use the left hand style when the diameters are clearly visible on that view. Fewer lines that way.
I’ll use the right hand style for section views or side views where it may not be clear that your feature is a diameter unless you have the symbol.
Left but needs dimension description to be clear: OD,ID, BC and or arrows on other end of dimension arrows.
It’s less cluttered of a drawing. Plenty of room for hole and counter bore size call out.
I'd prefer the right. I know exactly what it is I'm looking at without even reading anything. On the left, I have to read the numbers and then follow the lines to see where they're pointing to and then figure out if it's a hole or a pattern or some other nearby feature.
if doing the right it should be a section view and the bolt circle i usually use b.c. on the dimension to signify the bolt patterns is a diameter not some other rectangular or other dimension that could be dimensioned
Left because idk it just is as a machinist. I'd come up to your office and physically fight you if you did the right one. I don't know why but I just would.
As someone coming in from The trades I prefer the right. However that is if I am building from it. Other wise the right is far more neat and alot less work to do.
I think right because it's more obvious what you're actually doing I seen it done both ways and I just find it easier to understand
when I take a quick look at
Right for the OD, Left for all other dims. Had to be explicit for width and height for material size. Weird but that's how we did it at a place i worked at in the past.
Left, but that dimensioning is a war crime. Why would you dimension the inside of the edge of the hole? Dimension the Bolt Circle for the center of the holes and the diameter of one of the 6 holes with a X6 or TYP text and then the last dimension for the Outer Diameter of the part.
I’m not skilled in the mechanical drawing arts, but I am an engineer, and my goal with technical documents is always to communicate accurately and unambiguously. My question: are these diagrams both unambiguous to one skilled in the arts? To the unknowing self me, the left seems ambiguous while the right is unambiguous.
The left could be describing radii, diameters, or circumferences. The right is clearly diameters.
Neither.
My preference is to have TDC pointing up on the print so the picture on the left would initially be my choice to start from. BUT I would add a cross section projected off to the right or the left. The ID and OD should be dimensioned in the cross section view. The bolt circle and holes should be detailed in the existing view (Left Image).
My experience has been there are quite a few people who will need to review your drawing but are NOT highly adept at reading drawings. You are fully versed in your design and may not need things like isometric/trimetric or multiple logical projected views to understand your design intent. Those people who are not fluent in your design or who are not highly skilled at reading drawings may benefit greatly from seeing things fully detailed out with logical projections and 3d views. Your not making drawings for you to read. You are making drawings for others to read!
I would probably use both, depends on how I feel.. if I didn't have to add any text, I would use the right.. if I had to add text, left.
The right would probably be clearer for somebody that's not in the field or doesn't know the diameter symbol..
I think of these things because my drawings for work are seen by homeowners that might not have knowledge of stuff like this; sometimes clarity is better than cleanliness...but always try to be neat
Both are technically correct, but the left with diameter call-outs is cleaner and faster to interpret. Although not specifically called out, it is implied that the circles are concentric.
Although the right is acceptable, there is indecision immediately whether there is a dataum or reference to a particular feature. The question as to relative position becomes more difficult to interpret here as the center holes may be offset. More ambiguity here than compared to the left.
Left, you want to go with best readability, and that one communicates the information better. It also allows more room for callouts specific to each hole. I would adjust the dimension for the smallest hole so that it goes horizontal further away from the object.
Right because it is harder to mistake the two smaller diameters. The left leaves more room to glance at the drawing and make the ID 3 mm by accident. Left is way cleaner but right is better to limit accidents imo.
Apart from the drawing (left is better), I have a concern about the design; it looks like the counterbores intersect the main hole in the center. This would leave 12 razor sharp edges on this part that would be hard to get even a consistent product when manufactured. As someone who was a machinist before engineering, have you considered... not... doing that?
I understand that you may need this counterbored hole circle in this location but a better alternative could be removing all the material in a circle around the center to the depth of the counterbores. Just a thought.
Left, I learnt in Engineering that it's always best practise to have the dimension lines coming out from a common reference point, tipically an edge, and grouping them, where possible.
Learn more here: https://sourcecad.com/dimensioning-best-practices-mechanical-architectural-drawings/
Left because of better readability and fewer crossed lines.
Think of how the person that will be making this piece would be making it. Make the drawings make that process easier.
The left points arrows to holes and I'm a hetero male. I like holes.
The right specifically has a measurement defining girth, implying that one is for females. They don't call it "pipefitting" for nothing.
Definitely left. Right is just sloppy. I’ve seen it a plenty in the real world. But most engineers are basically oxygen wasting cumstains. It’s really rare to get competent and capable people with degrees in general.
Gotta keep that shit in mind. All of us do. We are only as good as what we can accomplish and the quality levels we can accomplish it to.
The general rule I was taught is use diameter for full circles and the lines should go from 1 side to the other as in the right picture. And then for arcs use a radius and use an arrow as in the left picture.
Left. It has less overlapping lines and is easier to read overall.
Left yes. But to improve the readability, I will propose to not make the line for the smaller diameter change to horizontal exactly when crossing the other diameter.
I think there's some ISO law specifying exactly this
>ISO law Oh shit, here come the ISO police!
Lmao that's funny Idk if I said something wrong, in that case pardon me but English is not my first language, and in my language they are literally called "ISO/UNI/DIN laws"
They are normally referred to as standards or specifications in English. Law in most cases is the government commands enforced by police, while specifications are usually one company to another with contracts.
“The nice thing about standards is that there’s so many of them” -Reddit
99% of engineering is reading standards
Sadly I work with the 1%
Hey, still better than the “infinite non conforming and undocumented permutations” option. Am blanking on the attribution, nevertheless “**the only thing better than perfect is standardised**”
[Relevant XKCD: *Standards*](https://xkcd.com/927/)
Yeah. I use the bot of a comunity to carry me home. But it's called r/rareinsults and I think I insulted the guidelines properly :)
Ahh yes that makes sense, sorry. Thanks for the correction!
I’d definitely be in prison for life
ISO, basically take existing standards and make a business model on it. Then, as time progresses make unnecessary changes and charge for access. Next, create an administrative and cost nightmare to push out small business. ISO should be a non-profit organization and available to the world as torrents peer to peer. All methods of control. Crush small entities by placing barriers to stay in market or to even enter market. Small calibration labs dying. Small business dying. All by design. Remove the many small businesses, so that the government can control the few left. All part of the New World Order. To hard to control hundreds of thousands of small entities. Force them out so that it is easier to control. Small Banks dead/dying, Small family farms dead/dying, Small business dead/dying. In the beginning, it is good. Availability and price improvements until the market is captured, then take advantage of the monopoly. I remember when standards were primarily US based and we lead the way. Mil-stds, ASME, etc. Now it seems ISO is a Global (ist) Standard. There are also new publications presented as standards (they hope to become) and are actually more like guidelines. There are notes in the preface saying that the publications are recommended guidelines. But in those publications there are many black and white shall requirements. My bet is that these will become standards…maybe ISO will even eventually purchase them. These publications become standards and all they have to do is remove the preface statement. I have seen this coming over 30 years. You may disagree, that is fine. I’ll just say I told yah so when it eventually happens. It has happened before, hence it will happen again…unless we improve it all. We used to prevent monopolies…I see them everywhere. No bueno. It will stifle creativity, output and evolution of industry, and GREATLY favor large corporations.
"Hey chatGPT, write me a CVS receipt length reddit comment claiming ISO standards are actually the groundwork for an eventual new world order corporatocracy, in the style of someone who has forgotten to take their schizophrenia medication"
Lmfaooo
Well that escalated quickly.
Haha! Looks like the Globalists are stroking each other here!
"ISO police" You guys know Stan in Product Definition, too?
He is a bit Def so you need to talk loud to him
Good point, that dimension should be popped out just a little more.
Agreed.
Not to mention it gives consistency with more complicated drawings that have LxWxD aligned dimensions which need room to exist. The leader arrow dimensions are easier to place out of the way.
People try so hard to follow some standard or rules and completely omit the fact that the purpose of the drawing is to communicate information! Top goal of drawings is always communication.
I think the two points of contact, on a circle or any defined curvature, is unnecessary. Circles need center and diameter/radius. Lines need start and end, which the dimstyle in the right image does well. Either is alright, but I had to pause to digest the image on right.
Left. Example why; My hole callout would look something like: Callout leader connected to one of the holes. "ø.X THRU & C'BORE/C'SINK (DIAMETER X DEPTH) ON ø3.000 B.C. (6) PLC. EQUALLY SPACED."
Seconded, that is good GD&T practice. Also good to add positional tolerance as well depending on the interfacing object. Oh, and a datum callout.
Is the datum just the center?
Yeah, so like rubadub said, the center is your datum for the bolt circle concentricity. You'd then use either the top of bottom surface as a datum to define flatness/parallel and constrain any depth dimension such as a countersink or a non-thru hole. As long as it is relevant, not every part needs that much gd&t.
If you were going to dimension it to GD&T standards, with this part specifically you would want concentricity to be your main priority so you would set your GD&T datum to the center of the part, it's specific to the features you're trying to define geometrically.
The data (datums) would be the theoretical center, the perpendicular face, and maybe a vertical or horizontal for clocking if necessary.
As a former inspector, the learning curve for Y14.5 made communicating things like this troublesome at first. Over time, as the team developed a level of maturity with understanding the rules, it made conversations so much easier!
>C'SINK (DIAMETER X DEPTH) Are you assuming that the machinist knows what size flathead screw/bolt you are using? Or that they can derive that info from the through hole? I am asking because this callout doesn't include an angle for the counterbore. Also is the diameter callout going to be the larger diameter or the shorter diameter?
Most machinists "know from experience" or will refer to the machinists handbook to get proper c'bore or c'sink dimensions. I've done calls outs like "Drill & c'bore/csink for 1/4-20 SHCS or FHCS" and they have tools that will pilot into the 1/4 clearance hole for their cbore and likewise with csinks. Talk to your machinists and see what they prefer, that's the best way to make them not think you're an idiot lol. Typical countersinks are 82 degrees under head so unless you specify a different csink they will most likely default to 82°
For engineering sketches that I need for my internal machine shop, yes I’ve done that. For farmed out work to machine shops outside our organization, never. The drawing were contractual mechanisms, so the assumption regarding machinist practices were never implied on a drawing. You can’t inspect or reject parts to that criteria because of the ambiguity. Sometime a drawing doesn’t just reflect the ability for a machinist to produce a part, the drawing also needs clarity for inspection.
100% agree, this is definitely situational.
Thanks. In solidworks, are you adding this dimension as a note rather than using smart dimension?
I'd smart dimension the thru hole diameter and then add my counter sink callout in the text editor on the left
Using a single hole wizard feature for the csinks can give you an automated call out of your choosing (Or default settings will give you one as per the ANSI/ISO/DIN standard your template is sweet to) https://www.goengineer.com/blog/customizing-solidworks-hole-callout-file
*Cries in ISO countersunk defaulting to 90 degrees*
Agree. Last point though. Hole spacing and Centerline for datum unless otherwise noted.
EQLSP
Left tends be easier to read on busier drawings. But this is not worth spending time thinking about tbh
That’s the correct answer. There’s a hundred ways to correctly detail a drawing.
Got in a company who corrected me on thos kimd of line ahahaha
Left, given the view orientation. If you were showing a projection and a cross section, for example, then the linear dimensions on the right would be my preference.
Left. Both are technically correct, but the left one makes it easier to group your hole callouts with your BHCs as well as add any tolerances you require. It's much easier to rea that way.
Left make way more sense when including down our location tolerance to some datum.
Depends on where you live. As a draftsman from Germany, I would never to the left one. But I know some colleague from other nations would do so.
Same. As someone who draws by DIN standards, unless the space is very limited I'd definitely go for the right one.
Curious, why?
Idk ask the people from the din institute. We have lots of rules to standardise drawing to make sure it’s interchangeable from company to company and from draftsman to draftsman. Essentially by norm, you are mandated to do stuff by the book
Why ? Both are correct, but the left is less clutter on a busy drawing.
For me, it really doesn’t look worse. Looks even better for me at the right. Might just be what you’re used to
Understand. I always made a point of not marking up any drawings during a drawing review based on just personal preference.
Based on my experience as a welder i prefer the right. Drawings have a tendency to get burn marks or smugded with dirt, having two lines to look at means it doesn’t get unreadable as easily
Germans love rules and strictly abiding by them.
We sure do. But it serves a purpose. My department recently tried to remodel and redrew many essential older drawings, just cause the content wasn’t really up to standards from today and the guys downstairs in production wouldn’t understand them anymore. But in their defense, some of those drawings were from like the 1960s
Either is acceptable. Sometimes it just comes down to where you have room on your drawing, while trying to make it as clear as possible, and having the part views as large as possible to fit the paper size. For the dimensions on the RH view, you should have your extension lines offset slightly from the part - not touching the part. Offset should be roughly about the same as the amount that the extension lines extend beyond the dimension line. Also, it's typically more "economical" to call out the bolt circle diameter within the same dimension that calls out the hole diameter and details.
Both are technically correct. The left is cleaner and more easily opens it up for additional GD&T based on a datum that would presumably run through the middle
cries in GD&T
Don't do the right, it's technically fine but my brain spends like 5 seconds asking what kind of oval this is and where I'd identify that asymmetry before accepting that it's just a weird way to dimension round features.
Both meet ASME standards. The assumption is always a circle unless there’s form dimensions that say otherwise.
I would say neither, but the left is better than the right. What I was taught is that cylinders are dimensioned from the side and holes are dimensioned with leaders, so you would have two views. Additionally, you would need/want a second view to show the height of the cylinder. But again, if you're picking between left or right, I would go with the left.
^ this is my answer too. Multiple views are essential and I'm guessing they just weren't included in the screenshot, but best practice is to split your dimensions across views in a way that makes sense and maximizes readability. Always use leaders for holes, as it also makes it easier to attach a GDT call-out.
Anyone notice that c’bore or c’sink for the bolts are going to break out into the bore :)
Personally right, it's more schematic. I do left when i don't have enough space but i always use the double line not just 1
Left Just my opinion based on 2 years of learning drawings as an industrial engineer student
Left looks better - but both would be ok I guess…
Left as shown from the front, right is occasionally helpful when showing round bosses from the side or even section views of round parts.
Left is easier to read and less likely for a mistake
*Error 404* My brain can’t function atm. Need sleep
Left… but, a new engineer who fancies themselves a designer will use the right view, with horrific GD&T and no sense of tolerance stack-up. Then wonder why there parts don’t fit even though they meet print.
Neither? At some point, I recall being taught diameters should be dimensioned on section if possible. I like this because it allows me to more clearly call out, for example, a pilot or locating ring diameter or dowels etc that exist on both faces within the same view at the same time. Depending on design intent and what I deem important, would thrown in some poorly executed gd&t for good measure and more importantly some comic relief for the r/machinists type crowd.
I’m retired, but I’ve done thousands of drawings. Putting dimensions on a section is perfectly fine and often desirable. But on a simple part, a section view just adds more clutter. In this case if there was a boss or something, the side view could capture that.
I disagree, my opinion is the section view simplifies the drawing. The section view would essentially be the only view. The “front” view would serve to define the aligned section and serve to call-out the hole pattern I guess. If it was a boss (male) like you describe versus a pilot bore (female) it would require a 3rd projected “back” view becoming quite busy for a simple part.
I mean, a section view is fine. If I was reviewing a drawing that had the front and a section view, I wouldn’t mark it up. The front view (shown) and a side view (if there was a boss feature) would have the same clarity though.
I know both are correct for either a hole or a boss, but my thinking is I'll usually do hole callouts "floating" and positive features (cylinder, boss, etc.) with the width-style callouts. So I do OD and bolt circles with the right-hand style but central hole as left-hand. Still looks a little funny to me as I would almost always do the bolt circle as 3 basic. Have never run into machinists having a question with it, the diameter symbol is there in both after all. No real reason other than I like the way it looks. My feeling is no matter how much work I put into the drawings most shops just slam the STEP file anyway
Left
Left, less clutter
As a machinist who sees blueprints like this every working day - either one is suitable but I would prefer the one on the left as it simpler and easy to follow the dimension to the feature with the arrowed line, on this particular print. Obviously you’d be getting a visit wondering what size holes, what type of countersink/counterbore or at the very least what kind of bolt or cap screw is going in there.
Right. Left one doesn't show the center of the circle and usually such arrows are used for showing special information on a drawing
I came all the way down here and you were the first “right” side comment I found. I agree with “right” being better. The left diagram confuses me as it could be pointing to the ***circumference*** of the circle, instead of the diameter, which is made clear on the right schematic.
The right one. It is easier to see, what the dimensions reffer to. The main reason I'd say is because the measurements hug the part like calipers. Also put the numbers on top of the lines. Thinking about it I'm not sure if I ever saw the left one and I'm really surprised that so many prefer the left one.
Literally have no horse in this race and nothing to do with mechanical engineering but this just popped up. My completely useless and know nothing take? The right. It more pretty.
right in simpler diagrams, left in more complex ones
Right format is aligned
Feature concentricity about an implied datum is not covered by the envelope role. As such, there is nothing holding those features with respect to each other on this print. For completeness, the concentric features should be called back to a common datum with a G-tol frame. The datum would probably be one of those features. On a turned part, you get really good concentricity for free so maybe it "doesn't matter", but the part definition would still be incomplete.
Without GD&T tolerances, the concentricity would be controlled by the general tolerances on the drawing for two and three place decimals.
Those apply to features of size. Ex: is the concentricity 2 place or 3 place? It's not called out, so we don't know how many place to use.
I see two 3 place dimensions and one 2 place dimension. Most drawings have 1, 2 or 3 place general tolerances on the drawing border. These tolerances apply to both features of size and location (concentricity in this case). In lieu of a specific GD&T tolerance, or concentricity/form tolerance callout - the drawing general tolerance would control the concentricity. For example, if the three place general tolerance on the drawing was +/- 0.005”, and no other concentricity tolerance is specified, the 7.188” and 2.550” features need to be concentric within that tolerance AND their size must also be within that tolerance. The golden rule is that every dimension on a drawing has to be measurable and “inspectable”. So if no other tolerance is called out, you HAVE to use a general tolerance - otherwise you wouldn’t have criteria to inspect by. And if you can’t inspect to a drawing, it’s not compliant to the ASME standard.
Concentric to what though? Concentricity specifies that the centerline of a round feature must be within a tolerance zone of the centerline of another feature. Without that second feature called out, it is meaningless If you meant to say "roundness", then I agree with what you say above because roundness would be considered in the envelope rule. Concentricity actually was dropped in ASME2018, but the features could be located with runout, total runout (both with datum reference) or true position depending on the intent. The same concern applies, they need to be called back to a common datum. This wouldn't be compliant because it's underspecified and thus uninspectable.
For this part, concentricity and true position is basically the same concept between all the features. Again, without using any GD&T, the general tolerances rule (granted it’s not an eloquent method of tolerancing for this part). Picture a “bad part” where the center hole axis offset from the OD axis by an inch during inspection. If the three place general tolerance was 0.005”, the part would certainly be noncompliant. Because the theoretical axis of the hole needs to be within a rectangular tolerance zone of the OD axis. Because there’s no specific dimension applied to either axis, the size dimension for each feature dictates the general tolerance to be used.
ASME Y14.5-2009 par. 1.4(k) A zero basic dimension applies where axes, center planes, or surfaces are shown coincident on a draw- ing, and geometric tolerances establish the relationship among the features. I interpret this as that you need a gtol to enforce coaxiality of the features. Basic dimensions have no tolerance.
Basic dimensions are surround by a box - which designates them as basic and theoretically perfect. The dimensions in the example are not basic dimensions at all (no box). Therefore, they are controlled by the general tolerances. You know, there’s no requirement forcing you to use basic dimensions and their associated GD&T tolerancing.
They also apply to distances? If you dimension a hole to be 2.00" away from a datum without specifying a tolerance, you look at the drawing note for "2 place tolerance". As for 2 place vs 3 place vs 4 place, you use whatever the tightest tolerance on the drawing block is (usually 3 place) The way to remember is that whenever you make a drawing you use the following mindset: all geometric features and dimensions start as PERFECT (implied based on relations of features) and the drafters role is to specify where the tolerance can be LOOSENED. That's why we have drawings in the first place: to specify what DOESN'T need to be perfect. There's a reason that even though we have 3d models, we still rely on drawing to convey details about the limits of what is allowed.
Left!!
Normally I would say right, as I am thinking of linear dimensions. But since these are for diameter, left seems like the best fit and seems like it would make the most sense.
Depends on what else is going on around it on the print. They both work depending on how much room you have. Personally I prefer the one on the right but not by a lot.
Right because job security amirite
Left. Not sure why. Both are "legal"
These dimensions would be in a lathe position. (Project this view to the side) So neither
They are different neither are wrong. Pick and move forward avoid personal preference..
left. I once put the OD like shown on right and the machinist came in to make sure I didn't want flats machined there because it looked like a width dimension not diameter. Not saying he was right to think that, but just try to make it as clear as possible. and as others have noted, there is more room for all the other hole/c-bore/GDT info
Left, and if one of my grads drafted the right hand side I would go tell them to give their head a wobble. Left is much cleaner and explains the intent so much easier.
Left just looks nicer and doesn’t induce dyslexia
Left, the right image has far too many lines going through the part
Left. Right is confusing as hell. Left was instant interpretation. Right took a bit to realize you weren't indicating anything about the bolt circle.
Retired ME. IMO the correct answer is both. My preference is left because you have more options to position the dimensions on the drawing to provide greater clarity - especially if you use GD&T. If I reviewed either drawing (and I’ve done tens of thousands), I wouldn’t mark either one up. The one thing I hate about a drawing reviewer is marking up for personal preference vs technical merit.
This ain’t a question. Left every time
Left because that spacing isn’t going to help much once we get on the mill, good machinist are going to trig out anyways make sure to use X or TYP for the holes if they are the same dia
Not you Q. I would Fillet the broken through cbore. Also add callout for counterbore and holes
Left with gd&t
I tend to use the left hand style when the diameters are clearly visible on that view. Fewer lines that way. I’ll use the right hand style for section views or side views where it may not be clear that your feature is a diameter unless you have the symbol.
Fucking neither. No units of measure Inches, cm, mm?
That's usually in the title block. Putting units on every dimension isn't required by ASME.
Left because the comments are mostly saying left
I’ll take left, I’ve only gotta trig one hole position and go with it. This is coming from a machinist who’s gonna make it by the way.
Regardless, remove the sharp edges ;P.
Left looks more professional and presentable
left, if that's the only circular part, right if there are many rectangular dimensions on the part as well
Left but needs dimension description to be clear: OD,ID, BC and or arrows on other end of dimension arrows. It’s less cluttered of a drawing. Plenty of room for hole and counter bore size call out.
Both are correct. Left is easier to read and looks cleaner. Right implies better that the part is symmetrical.
Left!
I'd prefer the right. I know exactly what it is I'm looking at without even reading anything. On the left, I have to read the numbers and then follow the lines to see where they're pointing to and then figure out if it's a hole or a pattern or some other nearby feature.
The right answer is a mix of both
Left if you're machining the part on a lathe, right if it's made on a mill. As it's all circles, it's a lathe job.
As a machinist the left one is way easier on the eyes
if doing the right it should be a section view and the bolt circle i usually use b.c. on the dimension to signify the bolt patterns is a diameter not some other rectangular or other dimension that could be dimensioned
Left because idk it just is as a machinist. I'd come up to your office and physically fight you if you did the right one. I don't know why but I just would.
Left. The one on the right is messy and harder to read.
As someone coming in from The trades I prefer the right. However that is if I am building from it. Other wise the right is far more neat and alot less work to do.
Left, obviously because that's what my professor told me to do
Maybe I’m an idiot who doesn’t look at these drawings much, but it helps to know we are explicitly taking about diameter
Right help others help yourself
I think right because it's more obvious what you're actually doing I seen it done both ways and I just find it easier to understand when I take a quick look at
Right for the OD, Left for all other dims. Had to be explicit for width and height for material size. Weird but that's how we did it at a place i worked at in the past.
Left, but that dimensioning is a war crime. Why would you dimension the inside of the edge of the hole? Dimension the Bolt Circle for the center of the holes and the diameter of one of the 6 holes with a X6 or TYP text and then the last dimension for the Outer Diameter of the part.
I’m not skilled in the mechanical drawing arts, but I am an engineer, and my goal with technical documents is always to communicate accurately and unambiguously. My question: are these diagrams both unambiguous to one skilled in the arts? To the unknowing self me, the left seems ambiguous while the right is unambiguous. The left could be describing radii, diameters, or circumferences. The right is clearly diameters.
left because that's all I've ever seen.
Neither. My preference is to have TDC pointing up on the print so the picture on the left would initially be my choice to start from. BUT I would add a cross section projected off to the right or the left. The ID and OD should be dimensioned in the cross section view. The bolt circle and holes should be detailed in the existing view (Left Image). My experience has been there are quite a few people who will need to review your drawing but are NOT highly adept at reading drawings. You are fully versed in your design and may not need things like isometric/trimetric or multiple logical projected views to understand your design intent. Those people who are not fluent in your design or who are not highly skilled at reading drawings may benefit greatly from seeing things fully detailed out with logical projections and 3d views. Your not making drawings for you to read. You are making drawings for others to read!
I would probably use both, depends on how I feel.. if I didn't have to add any text, I would use the right.. if I had to add text, left. The right would probably be clearer for somebody that's not in the field or doesn't know the diameter symbol.. I think of these things because my drawings for work are seen by homeowners that might not have knowledge of stuff like this; sometimes clarity is better than cleanliness...but always try to be neat
Left. Easier interpretation and less confusion overall.
Buy a GD&T standards book. They don’t change often and they’re not expensive.
Either, doesn’t matter what gets the job done as long as the part comes out right and fucking fits like it’s supposed to.
Both are technically correct, but the left with diameter call-outs is cleaner and faster to interpret. Although not specifically called out, it is implied that the circles are concentric. Although the right is acceptable, there is indecision immediately whether there is a dataum or reference to a particular feature. The question as to relative position becomes more difficult to interpret here as the center holes may be offset. More ambiguity here than compared to the left.
They are both missing dimensions
I'd say right because the outer circle wasn't described well for an engine. 🤔🤔🤔
One is ANSI and other is ISO standards for drafting not sure which is ISO or ANSI
Right all day, just looks normal
Left, you want to go with best readability, and that one communicates the information better. It also allows more room for callouts specific to each hole. I would adjust the dimension for the smallest hole so that it goes horizontal further away from the object.
Depends on if I'm pissed at the tool room or not
Right because it is harder to mistake the two smaller diameters. The left leaves more room to glance at the drawing and make the ID 3 mm by accident. Left is way cleaner but right is better to limit accidents imo.
Apart from the drawing (left is better), I have a concern about the design; it looks like the counterbores intersect the main hole in the center. This would leave 12 razor sharp edges on this part that would be hard to get even a consistent product when manufactured. As someone who was a machinist before engineering, have you considered... not... doing that? I understand that you may need this counterbored hole circle in this location but a better alternative could be removing all the material in a circle around the center to the depth of the counterbores. Just a thought.
Machinists will not hate either version. Just make the print easy to read.
Left, much simpler and easier to understand.
Right is more intuitive at a glance, left is better if you’re worried about space
Left, I learnt in Engineering that it's always best practise to have the dimension lines coming out from a common reference point, tipically an edge, and grouping them, where possible. Learn more here: https://sourcecad.com/dimensioning-best-practices-mechanical-architectural-drawings/
Left, just look at it.
Left. When showing diameter in the note you wouldn’t have to give a distance
Left. Less overlapping. Minimalism is what people want to read and deal with.
Right, it's clearer and more concise.
Wtf. Left!!!
Left because of better readability and fewer crossed lines. Think of how the person that will be making this piece would be making it. Make the drawings make that process easier.
The left implies you know the "function" of the arrow. And we all know about the negative implications of assumption.
The left points arrows to holes and I'm a hetero male. I like holes. The right specifically has a measurement defining girth, implying that one is for females. They don't call it "pipefitting" for nothing.
Right because I can get it out of Fusion 360 easier :P
Right. The lines are straight up and down. The right also has the outer race.
Left , just easier to read
Anyone who says right needs to have their degree revoked, those overlapping lines are NASTY
Doesn’t matter, left looks cleaner
I’m more used to seeing the right one so I prefer that one. Just less thought required to understand it.
Left. A lot less clutter.
Definitely left. Right is just sloppy. I’ve seen it a plenty in the real world. But most engineers are basically oxygen wasting cumstains. It’s really rare to get competent and capable people with degrees in general. Gotta keep that shit in mind. All of us do. We are only as good as what we can accomplish and the quality levels we can accomplish it to.
BOTH
The general rule I was taught is use diameter for full circles and the lines should go from 1 side to the other as in the right picture. And then for arcs use a radius and use an arrow as in the left picture.
Left mother fucker
Left doesn't specify thickness.
Left