Which is most prefereble Dimensions method?
Which is most prefereble Dimensions method?
(OP)
Dear All!,
As we are making GI Sheet metal and Busbars Drawings for Electro Mechanical Products, Please let me know which is the best method to call the dimensions,1.) Ordintate Dimensions(Pick two faces and give X and Y dimensions) 2. EDGE to Hole and then Hole to Hole, Tolerance used in parts are ISO2768-M.
Thanks in advance
Best Regards
Asit Rathod
As we are making GI Sheet metal and Busbars Drawings for Electro Mechanical Products, Please let me know which is the best method to call the dimensions,1.) Ordintate Dimensions(Pick two faces and give X and Y dimensions) 2. EDGE to Hole and then Hole to Hole, Tolerance used in parts are ISO2768-M.
Thanks in advance
Best Regards
Asit Rathod





RE: Which is most prefereble Dimensions method?
Leave ISO 2768 for non-locating dimensions.
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Which is most prefereble Dimensions method?
Both of your proposed methods are approved by the standards. Which of them will be clearest to the end users of your drawings?
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JHG
RE: Which is most prefereble Dimensions method?
RE: Which is most prefereble Dimensions method?
RE: Which is most prefereble Dimensions method?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Which is most prefereble Dimensions method?
Thanks for the sharing the knowledge.
CH, our LOCAL MFGs are not able to understand feature control Frames,
Drawoh,Randomdrafter & TICK, current situations we give ordinate dimensions and give flat pattern to the LOCAL MFGs so they can get RAW Size from the flat pattern.
KENAT, We already give Tolernace in Dim of the hole.(e.g. M5 screw we give 6.0 mm hole)
Regards
Asit
RE: Which is most prefereble Dimensions method?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Which is most prefereble Dimensions method?
Do you have any standards to be followed? or what best practise you are following.
Thanks in advance.
Regards
Asit
RE: Which is most prefereble Dimensions method?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Which is most prefereble Dimensions method?
Only threads/chamfers will be done after forming.We will not include these dimensions in flat pattern drawing.
If we need tighter tolerances those holes are done after forming.
There are various checks run on the flat pattern view to see all holes are as per standard/any break in profile etc....
RE: Which is most prefereble Dimensions method?
Yes same our mfg did it for Sheet metal parts, first nesting (Diff sizes, set in raw material sheet), and then punching and then cutting at last bending, and then Assembly HW fitting like rivets, Pop nuts
Regards
Asit
RE: Which is most prefereble Dimensions method?
Engineering drawing typically documents the finished item without specifying process unless process directly impacts end functionality. So dimension scheme & tolerancing needs to capture function first.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Which is most prefereble Dimensions method?
Atleast in some area of sheet metal work hammer will take care any variation at end ;)
RE: Which is most prefereble Dimensions method?
" Only when there is tighter tolerance required we can change the scheme and go with GD&T"
This is the real world perception! (or at least some of the manufacturing companies act according to the quote above)
RE: Which is most prefereble Dimensions method?
This is not what any drawing standard I'm aware of says or implies.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Which is most prefereble Dimensions method?
So whenever some critical requirements arises instead of our regular process [Ordinate dimensioning with default tolerances], we change to +/- tolerance or FCF wherever required. in some cases we even do machining in assembly. As far as I know there is very few issues arised over the years.
RE: Which is most prefereble Dimensions method?
The part still needs to function. Nothing is more important.
RE: Which is most prefereble Dimensions method?
John Acosta, GDTP Senior Level
Manufacturing Engineering Tech
SSG, U.S. Army
Taji, Iraq OIF II
RE: Which is most prefereble Dimensions method?
RE: Which is most prefereble Dimensions method?
John Acosta, GDTP Senior Level
Manufacturing Engineering Tech
SSG, U.S. Army
Taji, Iraq OIF II
RE: Which is most prefereble Dimensions method?
RE: Which is most prefereble Dimensions method?
As a practical manner, it's only when tolerances are nearly the same as acceptable variation that FCFs are valuable. When the variation is a small portion of the available tolerance there's little value in making the effort to precisely describe the factors governing inspection.
One might suggest that it's always the case that a precise description is required, even when the tolerances are large, but if an organization has control of the production process and the design won't be floated to outside organizations, then there's no reason to not take advantage of the existing controls. For example, in four-color printing the tolerances involved put most metal work to shame, but the equipment and the setup is understood and your newspaper, magazine, or t-shirt come out OK.
OTOH, if production capability is on the edge of design requirements (either direct limits or 3 or 6 sigma boundary) then the increased precision of the description can help separate out the usable parts from those not usable.