In a message dated 3/2/01 12:04:21 PM Pacific Standard Time,
chuckc@attglobal.net writes:
<< The bolts in question appear to be 3/8 x about 20 tpi
with rounded crests (I think) and a greater thread angle
than on a US 3/8 nc bolt. <<
Chuck
First of all if it is a 3/8" bolt with 20 TPI it could very well be a BSF
(British Standard Fine). They do sometimes appear coarse when compared to
SAE Fine/American Standard threads.
>>I held it up to a 1/4x20 and the threads were the same
per inch; I counted and got 15 threads on the
3/4 inch bolt which makes about 20 tpi. Guess that
makes it CEI (Cycle Engineers Institue/British Standard Cycle),
right? Where I gonna find one of those? >>
Not necessarily, the modern CEI/British Standard Cycle threads are ALL 26 TPI
no matter what the bolt size is i.e. 1/4" through 1/2", it was only the older
Cycle threads that had 20 TPI. Once again "British Tools & Fasteners" has
these (the newer Cycle threads with 26 TPI) but I doubt now that is what you
have.
>From what you describe (3/8" with 20 TPI and rounded crests and roots) my
money is on BSF since there is no other bolts that I know with these
dimensions.
Curt Arndt
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