Gary,
There are two BSW standards. Originally, the head of a BSW bolt was one
size larger than the same diameter BSF bolt. So for a 1/4" BSW bolt,
the distance across the flats can be either 0.525" or 0.445". 5/16" BSW
is either 0.600" (old standard) or 0.525" (new standard). On some
wrenches you'll see both markings (1/4" BSW, 5/16" BSF).
Source: https://en.wikipedia.org/wiki/British_Standard_Whitworth
Cheers,
Bob Haskell
Austin Healey 3000 BN7/BT7 registrar
On 1/18/21 3:03 PM, warthodson--- via Healeys wrote:
> Sorry for the spelling error (Whitworth not Witworth). As soon as I
> read my email it was obvious to me.
> Gary Hodson
>
>
> -----Original Message-----
> From: warthodson--- via Healeys <healeys@autox.team.net>
> To: healeys@autox.team.net <healeys@autox.team.net>
> Sent: Mon, Jan 18, 2021 10:16 am
> Subject: [Healeys] 100 Generator Witworth bolt
>
> After our recent discussion about the 5/16" BSW (Witworth) bolt that
> threads into the aluminum end plate on the generator, I decided to
> search thru all my ziplock bags of British bolts to see if I could
> locate that one bolt. My 100 shipped disassembled. First, I separated
> all the 5/16" X 18tpi (coarse) bolts from the rest. Then I separated
> all the bolts with heads that fit a 1/2" socket because I understood
> that the 5/16" BSW bolts have a larger head. I was left with 2 bolts.
> They are identical, except that one is about 1/2" long & the other is
> about 7/8" long. Neither has any markings on the head of the bolt.
> My questions are:
>
> If one is for the generator, where does the other one go?
>
> The hex head on both bolts fit a King Dick socket marked 1/4W. The hex
> head measures 0.52 across the flats. According the a "Key to Nut &
> Bolt Sizes" chart I have, this head size should be on a 1/4"W bolt but
> the bolt is 5/16" diameter X 18TPI. Do you see the contradiction?
> Also, this chart indicates the hex head should measure 0.60 across the
> flats for a 5/16" BSW bolt.
>
> Gary Hodson
> _______________________________________________
> Support Team.Net http://www.team.net/donate.html
> Suggested annual donation $12.75
>
> Archive: http://www.team.net/pipermail/healeys
> http://autox.team.net/archive
>
> Healeys@autox.team.net <mailto:Healeys@autox.team.net>
> http://autox.team.net/mailman/listinfo/healeys
>
> Unsubscribe/Manage:
> http://autox.team.net/mailman/options/healeys/warthodson@aol.com
>
>
> _______________________________________________
> Support Team.Net http://www.team.net/donate.html
> Suggested annual donation $12.75
>
> Archive: http://www.team.net/pipermail/healeys http://autox.team.net/archive
>
> Healeys@autox.team.net
> http://autox.team.net/mailman/listinfo/healeys
>
> Unsubscribe/Manage:
> http://autox.team.net/mailman/options/healeys/rchaskell@earthlink.net
>
_______________________________________________
Support Team.Net http://www.team.net/donate.html
Suggested annual donation $12.75
Archive: http://www.team.net/pipermail/healeys http://autox.team.net/archive
Healeys@autox.team.net
http://autox.team.net/mailman/listinfo/healeys
Unsubscribe/Manage:
http://autox.team.net/mailman/options/healeys/mharc@autox.team.net
|