ACME Thread

[ITBT]

Hi,

Wish to know what thread designation of 1-3/4"ACME-2G means. 2G must be the tolerance of male thread, but what exactly is the tolerance and what is the designation for female thread? Any idea is appreciated.

Happy new year!

 

[israelkk]

FED-STD-H28/12A at

http://assist.daps.dla.mil/eAccess/index.cfm?ident_number=53613

 

[Sparweb]

Have you checked the Machinery's Handbook?


Steven Fahey, CET
"Simplicate, and add more lightness" - Bill Stout

 

[israelkk]

If the previous URL does not work try

http://assist.daps.dla.mil/quicksearch/

and search for FED-STD-H28

 

[BillPSU]

Invest in a Machinery's Handbook, its the best gneral reference you can have on anything about machinery.

Bill

 

[Cockroach]

"2G" is a general fit, as opposed to "1G" and "3G" for tight and loose fit between box and pin.

Yes, the 2G is applied to the joint, but is specified as "2A" for the pin or screw, "2B" for the box or nut. You would call out 1.750-6 ACME-2A for a 6 tpi pin and 1.750-6 ACME-2B for the corresponding box.

The tolerance as well as thread allowance is governed by the classification of thread. As mentioned, Machinist Handbook is a very good place to start.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[rorschach]

cockroach, you are wrong. 2A and 2B are designations for UN threadforms. 2G (General Purpose)is used for both internal and external acme and stub-acme threads unless they are of the centralizing type then the designation is 2C.