Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations IDS on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Need UNC & Acme Thread Gauge Dimensions Please

Status
Not open for further replies.

sprintcar

Mechanical
Oct 16, 2001
763
Anyone have a chart or website of dimensions required to machine thread gauges? I had a chart a few years back but they changed my computer and nuked half the hard drive data.

Web search hasn't turned up anything worth a darn yet, but I'll keep trying.

Need Male and Female (ie stud and nut)Gauge dimensions for 1.25 and 1.75 UNC for now.

Thanks in advance!

"If A equals success, then the formula is: A = X + Y + Z, X is work. Y is play. Z is keep your mouth shut."
-- by Albert Einstein
 
Replies continue below

Recommended for you

Thanks folks!!

"If A equals success, then the formula is: A = X + Y + Z, X is work. Y is play. Z is keep your mouth shut."
-- by Albert Einstein
 
The ANSI book should be here in a week or 2 according to our Purchasing Dept.
Meantime - would one of you be kind enough to give the ANSI dimensions for this one?
1.25 UNC
GO gage, plain ring, to check External thread (at Max mat'l condition) and Internal Thread Plug (ditto)

Thanks again!

"If A equals success, then the formula is: A = X + Y + Z, X is work. Y is play. Z is keep your mouth shut."
-- by Albert Einstein
 
Finally got the Machinery Handbook (27th) back and I'm a bit confused.
Reading the specs: Table 5 (pg 1918)
Plain gage, Major Dia of Ext thread (ie shaft)
GO = Max Major dia, gage tolerance is minus
Plain gage, Minor Dia of Internal thread (ie nut)
GO = Max Major dia, gage tolerance is plus


For 7 pitch, the gage tolerance is 0.0007"
So for a 1.25-7 UNC 2B male thread, the Max Major Dia is 1.2478 minus the gage tolerance yields a gage diameter of 1.2471
OR - does the gage tolerance subtract from the 1.250 3A diameter for a gage diameter of 1.2493?

It would seem to me that the 0.0007 should be added to the Major diameter 2B dimension so the gage can be threaded on. This way parts at the Max Mat'l limit would still pass.

Do I just have my Blonde hat on today or is the chart BassAckwards?

Thanks!


"If A equals success, then the formula is: A = X + Y + Z, X is work. Y is play. Z is keep your mouth shut."
-- by Albert Einstein
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor