Ray,
While the coding system works well for UNF fasteners, and sadly there is no
similar system for the Whitworth fasteners on the BN1/2s.
The part numbers that you refer to in the parts book will not help you to
decode the fastener sizes since they are just that, part numbers!
Most of the fasteners on the 100s, engine transmission and suspension are
Whitworth, specifically BSF (British Standard Fine.) There is at least one BSW
(British Standard Whitworth, coarse threads) bolt on the engine and some BSP
(British Standard Pipe) threads also. Most of the BA (British Association)
fasteners are found on the "Smiths" Instruments and the fuel pump and related
items, not to mention the assorted threads on S.U. Carburetors.
Trivia: The 4 types of Whitworth fasteners are BSW, BSF, BSP, BSPT (British
Standard Pipe Tapered), due to the 55 degree angle between the threads.
BA threads are a anglicized metric thread developed from the Swiss small
screw standard. Their angle between threads is 47 1/2 degrees
Give me a call if you have any specific questions.
Cheers,
Curt Arndt - Concours Committee
Carlsbad, CA
'55 BN1, '60 AN5:{)
In a message dated 6/20/05 2:37:36 PM Pacific Daylight Time,
gonzo18@mindspring.com writes:
<< I have the official parts book and the list of codes used for UNF
fasteners. With that the three letter and four didgit part number in the book
can be
translated into type,size, length and finish of any fastner listed.
Example (HZS 0506) That works fine for BN-2 thru BJ-8.
Is there any way of extracting similar information from the part numbers for
the BN-1? They would be BSW, BSF or BA as they were before the switch to
"Unified Thread Size"on or about 1955. Those part numbers are one didget one
letter followed by three or four didgets (2K 3092 or 7H6701) If there is any
logic to these numbers some of you guys must have figured it out and I sure
could
use the information.
Help me Obiwan you're my only hope!
Ray Juncal
Toot toot!
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