can someone confirm that i have the right size drill bit for a 7/16 unf tap i found this link and it says i need a 9.9mm drill bit, is this correct

http://www.tapdie.com/html/tapping_drills_for_taps.html

Thanks Antony

Yep. 9.90mm (0.3898" ) according the the wonderful Zeus book. The BSI alternative drill is 9.80mm, just depends what material you are tapping...

David

[Edited on 7/2/06 by flak monkey]

making some seatbelt mounts to weld into my roll bar so was going to use ordinary mild steel solid bar
drill a hole down the middle and tap out

9.9mm it is then
thanks for that

Antony

I used a 3/8 drill for mine. Worked a treat.