BRITISH STANDARD BRASS
BRASS THREADS (British Standard Brass)
Because brass tubing has a uniform wall thickness, irrespective of the tube
diameter, any thread cut on, (or in) it, would
have to have the same depth, so 26 tpi is standard on all diameters. An example
would be the thread cut on the brass
trumpet horns of the 30s cars, although many were die-cast rather than brass.
If it were 1" O/D, the thread would be 1"
Brass, 26tpi.
BSB has a 26 TPI pitch through the whole range and is often confused with BS
Cycle thread the difference being that brass thread has an angle of 55 degrees
whereas Cycle is 60 degrees. Brass threads are usually confined to fittings
and adjusters on cables.
Brass thread taps and dies are sold and advertised as 26 tpi and are identified
by the letters BSB.
These are a special order item.