Somehow my first message has dissappeared into that never land of ether
email. So, just to show it was sent I have forwarded the message again
from my sent mail folder.
Regards,
Blake
P.S. I've also corrected the ANC
-------- Original Message --------
Subject: Re: Nuts and Grease Gun
Date: Thu, 24 Feb 2005 10:57:40 -0800
From: yd3@nvc.net
To: mgs <mgs@autox.team.net>
References: <5.1.0.14.1.20050224014446.032d6030@mgaguru.com>
BSF is not the same as SAE fine. At one time MG used a British thread
designation Unified National. Unified National is very close to
American National. The only slight difference is the shape of the
crests and roots of the threads. Look at page H.16 of a TD series shop
manual. The TD used Unified National threads on later rear axles.
BSF standards for British Standard Fine. It's thread pitch is different
than American Natinal Fine.
Thread Pitch (Threads/inch)
Nominal Diameter UNC/ANC UNF/ANF BSW BSF
1/4 20 28 20 26
5/16 18 24 18 22
3/8 16 24 16 20
7/16 14 20 14 18
1/2 13 20 12 16
9/16 12 18 12 16
Thus the BSW (British Standard Whitworth, a course thread) matches the
thread pitch for the most part of Unified Course (or Amercan National
Course) in all sizes except 1/2 inch. However I think there may be a
difference in the thread angles. I would have to do some more checking
on that.
But BSF IS NOT the same as Unified National Fine in thread pitch. See
the chart above.
Regards,
Blake
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