Hy guys,
my request is not strictly related to VTR, but you are the only ones I know that can help me with UNF and withworth screw thread.
I have some aircraft bolts, screws, and nuts (NAS 1303, NAS 333 for example) and I need to buy taps and die for them. I suppose that the screw thread should be a UNF 10-32, but I have a little dubt that it could be a 3/16-32 BSF Withworth Fine.
Can someone confirm the 10-32 thread?
Is there a trick to easily distinguish those similar thread? The nut diameter difference is so slight that I find it not significative.
Thanks in advance
Bye.


PS. millimeters rulez, inches sucks!!!!

 

Really close to the same thing. 0.18 and 0.19. Where did you get the bolts? Finding out what they were made for might help a lot.

 

Update: NAS 1303 is 10-32, http://www.coastfab.com/boltsseries.html

 

OK, but there is also another difference: the angle of thread coil is 55° for withworth and 60° for UNF.

They came from Alitalia mainteinance service.
They were used on MD80 aircraft.

Thanks. That's what I was looking for!!!!