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Message |
    
Ted Shelton
Member
Username: ted655
Post Number: 27
Registered: 07-2006
| | Posted on Tuesday, January 15, 2008 - 07:07 pm: | 
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I guess I need a primer on bolt threads.
MM-fine or coarse, SAE-fine or coarse These I get. I thought my AQD40A would be metric, but on the head of an alternator bolt it has UNF stamped on it. I tried cleaning the threads with a M12-1.5 die. Close, but shaved the dia. down a bit.
I can buy a bolt, BUT I need to tap the block hole to clean the rust out. I don't want to wreak it, then I'm in big trouble.
What the heck IS a UNF & what tap/dies do I use? Thanks. |
Darren Morgan
Member
Username: darren1
Post Number: 6
Registered: 10-2007
| | Posted on Wednesday, January 16, 2008 - 01:02 pm: |
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UNF stands for unified fine and is an imperial system. The bolt be sounds like it is 1/2 inch UNF. You sould be able to source a tap fom an engineering suppliers. |
Ted Shelton
Member
Username: ted655
Post Number: 28
Registered: 07-2006
| | Posted on Friday, January 18, 2008 - 04:35 pm: |
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It was a 7/16-20 UNF (SAE-NF), but the hardness rating was metric, 8.8. (just to confuse us Yanks, I guess) I bought a new stainless steel bolt, SAE 7/16 NF. It fit perfect. Thanks for the advice. |
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