Strange GDT callouts

[DeWain]

We are quoting a new job, but the print has a strange general call out box. Look at the attached PDF. We understand the profile & true position but if you look at the tolerance part the is a /1 next to the 0.007 tolerance. Any ideas as to what the /1 means? Our engineer, QA manager and I are stumped.

 

[KENAT]

Assuming this is an inch drawing then I'd say the /1 might mean Per inch? As in .007 per inch.

Anyway you can ask the customer to confirm?

As to whether it's really legal or meaningful I'm not so sure, what drawing standard does this drawing claim to comply with?

forum1103 is generally a better place for this kind of question.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[drawoh]

DeWain,

They are quoting datums A and B. Usually, you need three datums to fixture a part for inspection, as per ASME Y14.5M-1994. Perhaps they do not understand the standard.

Foundries routinely quote .005"/inch for linear tolerances on investment castings, permanent moulds and diecastings, so KENAT's comments make sense to me.

JHG

 

[btrueblood]

I'll 3rd Kenat's post, and add I don't think the usage meets any known drawing standard. General tolerances of that sort are usually spelled out in a drawing note.

 

[mechengdude]

call the design authority and ask them. problem solved.

 

[rerig]

Kenat is correct per ANSI Y14.5M.

the /1 is tolerance per 1 unit of how the total length is measured.
i.e. inches, millimeters, etc.

 

[NomLaser]

Agree with Kenat and now rerig.