Hello,
I'm about to purchase some taps and dies to clean up some bolts, etc, and retap some captive nuts in the FC.
Am I correct in assuming that the early Holdens are UNC & UNF thread?
Regards
Edward
Thats correct Edward, UNC & UNF, would suggest some die nuts too if you can afford them.
John M
John,
I purchased taps and dies, and cleaned up a few nuts and bolts. Now the nuts spin onto the bolts!
Simple pleasures....
Seeing it was 20 years ago that I completed year 8 metalwork, I'm a little bit rusty on some of the tecnique with tapping new holes. What's the relationship between the hole diametre, and the tap that is required to tap it.
ie, Do I bore a 5/16 hole for a 5/16 tap, or should it be a 1/4 or 9/32?
No doubt there is a published table that identifies this? Any advice would be appreciated.
Regards
Edward
Edward,
I did a quick search and came up with a figure 55 -75% of the major diameter as depicted in the image below.
(http://www.parktool.com/images/repair_help/thread.gif)
You could also have a look here http://www.cartech.com/machining_zone/tapping.html which has enough info to keep you amused for hours on end. ;D Even has formulas!!! WOOHHHOOO ;D
(http://www.cartech.com/machining_zone/images/tapping_formulas.gif)
Cheers,
Craig.
P&N (cutting tool makers) put out a really good chart that covers a wide variety of threads but I am not too sure where you could get one. Perhaps Blackwoods or one of the other engineering supliers.