Author Topic: BSF  (Read 1973 times)

Offline kayzed1

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BSF
« on: February 19, 2020, 12:22:55 PM »
i have a couple or four studs to make for a mates dad's old BSA motorcycle side car, they are 7/16 and also a couple of 3/8th BSF threads...could some find person tell me the hole size and bar size i need to do these :doh: ..much grassy arse...i can do metric but have forgotten all the stuff my dad and school taught me..
Many thanks..Lyn.

Offline Joules

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Re: BSF
« Reply #1 on: February 19, 2020, 12:50:50 PM »
The tapping drill sizes are:

3/8" = 8.3mm
7/16" = 9.7mm

Bar size

3/8" = 9.5mm
7/16" = 11.1mm

Hope that is the info you want Lyn.
Honour your mentors, and pay it forward.

Offline Lew_Merrick_PE

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Re: BSF
« Reply #2 on: February 19, 2020, 01:17:43 PM »
The attached document is written for 60° V-threaqds (though it ought to be fairly simple to recalculate "factors" for Whitworth threads  --  I have never had a need to do so.  --  Lew

Offline tom osselton

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Re: BSF
« Reply #3 on: February 19, 2020, 06:01:59 PM »
I cut down some bolts and just rethreaded them using a 55 degree hhs cutter it worked out fine.

Offline kayzed1

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Re: BSF
« Reply #4 on: February 19, 2020, 06:56:15 PM »
Many thanks one and all, i will do the deed tomorrow now. :thumbup:
Lyn.