2.75-8 Stub Acme M2 - 2G 1

[Edfox023]

Can anyone tell me if the thread form of Stub Acme M2 and standard Stub Acme are the same? I know the pitch and minor diameter's are different, but what about the thread form itself? Thanks in advance.

 

[axlechaos]

Check out Machinery's Handbook, it has all the thread forms in detail - including ACME.

 

[Cockroach]

They are not.

2.750 - 8 Stub Acme-2G
c/w 45 Deg End Chmf
EXTERNAL (A) INTERNAL (B)
Major Dia. 2.7500/2.7437 Minor Dia. 2.6750/2.6812
Pitch Dia. 2.6992/2.6786 Pitch Dia. 2.7125/2.7331
Minor Dia. 2.6550/2.6344 Major Dia. 2.7700/2.7906

2.750 - 8 Stub Acme-2G-M2
c/w 45 Deg End Chmf
EXTERNAL (A) INTERNAL (B)
Major Dia. 2.7500/2.7437 Minor Dia. 2.6875/2.6938
Pitch Dia. 2.7055/2.6849 Pitch Dia. 2.7188/2.7393
Minor Dia. 2.6675/2.6469 Major Dia. 2.7700/2.7906

Both have the same lead for single start thread. The M2 is somewhat taller and fatter in the root of the thread (0.0413,0.0527), compared with the standard Stub Acme alternative (0.0475, 0.0511). But both use the same wire in the three wire measure when gauging, 0.07217 diameter. All measures given are imperial inches.

Hope this helps.

Regards,
Cockroach