Unidentified Bolt

[Bill Tattersall]

I have a bolt that measures .486 and has a thread pitch of 12 tpi by my gauge. This does not seem to be any metric size nor is it, obviously, a standard 1/2-13. Any ideas?

 

[george md]

That is us standard 1/2 x 12 as opposed to NC

1/2 x 13 . I had a tap at one time , but it's

been broken from using it in an NC hole to clean

threads. USS was popular in the early 1900's.

george

 

[Bill Tattersall]

Thanks George. Any idea where I can get 2 nuts?

 

[oj]

12 threads per inch is a British Standard Whitworth, 1/2 bolt, rather than UNC...

 

[charlie wise]

You can e-mail me Pretty sure I have one . where are you located?

 

[Russ from MN]

Like George said, 1/2 x 12 was fairly common about 1900. We had one piece of machinery at the paper mill I retired from that had 1/2 x12 bolts. I have an old set of taps and dies that have that pitch, if I had a lath and some 3/4 hex stock I could make you some. If you could find a tap and get some 7/16 heavy hex nuts you could drill them out and retap to 1/2 x 12.

 

[Bill Tattersall]

This site and you guys are the greatest. I work on a lot of old British cars and, several years ago, I picked up a set of Whitworth taps and dies while on a trip to new Zealand. I just looked and, low and behold, I have a 1/2-12 tap in that set. I can make my own nuts. Thanks to all.

 

[JMS/.MN]

During college, late 60s, I worked in a factory making furniture carving and duplicating machines. St. Paul Machinery....lots went to factories in VA and NC. They used a 1/2-13 setscrew on the pivot arms. I made the locknuts out of 1/2 inch std nuts, running a tap through them.

 

[Goose]

Think about what you just said.

 

[Anonymous-0]

Try Mcmaster-carr?

 

[Ian Beale]

Bill,

I see that it has been sorted.

Down here (OZ) we live with this problem that unified threads didn't solve

 

[Jim from Pa]

Try here.

http://www.tapsndies.com/catalog/item/6890755/6857169.htm

 

[Janicholson]

If the 12pitch are US made the whitworth might not work. the thread angle is %% drgrees, not 60! Jim

 

[Janicholson]

55 degrees, not 60. Jim