MadModder

Gallery, Projects and General => How do I?? => Topic started by: kayzed1 on February 19, 2020, 12:22:55 PM

Title: BSF
Post by: kayzed1 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.

Title: Re: BSF
Post by: Joules 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.

Title: Re: BSF
Post by: Lew_Merrick_PE 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

Title: Re: BSF
Post by: tom osselton 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.

Title: Re: BSF
Post by: kayzed1 on February 19, 2020, 06:56:15 PM

Many thanks one and all, i will do the deed tomorrow now. :thumbup:
Lyn.