tolerances

[jprobst]

When a tolerance is not called out on a print for hole location, what is the industry standard?

[cncsdr]

There should be a spot in the heading that says all other tolerance.

[jprobst]

no tolerance listed on print except for the cut length of the part

[Mcgyver]

the answer requires context. this might be viewed as an aberration in commercial circles, it is common if not the norm in model engineering/home shop plans where the builder does have complete knowledge of the mating parts and function. you pick a fit based on the intended purpose

edit: I'd add to that answer, if tolerances aren't stated they can be inferred from the number of significant digits in the dimension, but it would help in answering if you described the type of plans, part, function etc as if they are diy plans tolerances and clearance are usually up to you

[jackson]

no tolerance listed on print except for the cut length of the part

You may have to refer back to the customer "better to be safe than sorry"!!!!!!

[RICHARD ZASTROW]

I agree with jackson. I've seen where a complete book of "standards" is supplied with the RFQ. Many large companies have their own standards for materials, coatings, plating, dimensional tolerances etc. So, like jackson said, better to be safe etc.

[tomekeuro85]

99% of the time you'll be safe with +/- .005, and if they are reamer holes that are to be spaced a certain distance apart, we get +/- .0005. If you have a cnc and type in the right coordinates, you should be fine. Unless the piece is not on size.

[PBMW]

There is no "Industry Standard" if it isn't on the drawing then you need to call the customer. End of story. Assuming a number will get your parts rejected.

[cnc-king]

There is no "Industry Standard" if it isn't on the drawing then you need to call the customer. End of story. Assuming a number will get your parts rejected.

general machine shop practices dictates +.003/-.002 on hole sizes up to .25 in dia from .251 dia tolerance is +/- .005 but most company have their own tolerance standards that they follow and is supplied with their RFQ

[gizmo_454]

Yesteryear, that may apply. Unfortunately, more and more I am finding that companies are deviating from the norm and using their own tolerances. We have jobs that run in our shop that have 3 place decimal tolerances of +/- .015 on down to +/-.001. It just seems to depend on the customer and what their needs are as to what their "standards" are. When in doubt, always ask the customer. As said before in this thread, better to be safe than sorry. A phone call is a lot cheaper than having to run the job over because it was assumed.

[ImanCarrot]

When you do contact the customer, get it in writing. If you feel akward asking him to put it in writing then write to him yourself saying "further to our recent conversation, I confirm that we shall hold tolerance on dimension X to +- whatever".

[jackson]

When you do contact the customer, get it in writing. If you feel akward asking him to put it in writing then write to him yourself saying "further to our recent conversation, I confirm that we shall hold tolerance on dimension X to +- whatever".

Yes or just have them e-mail or fax another copy of the print that has it written on it such as .250 drill +.003 / -.001 PER. John Hancock