BSW (British Standard Whitworth) A coarse thread devised and standardised at Manchester in 1841 by British Engineer Sir Joseph Whitworth (1803 - 87). It is used in many types of engineering throughout the world, although in Britain its use is now being superseded by the ISO metric system. Angle of Thread = 55 ° Sizes range from 1/16" to 2-1/2"

Most, if not all, British cars, motorcycles, airplanes and machinery up the 1970s – and possibly beyond – used Whitworth thread forms. Sir Joseph Whitworth was born in 1803 in Stockport, in a grimy area of the industrial north west of England. Coincidently, not …

Thread Major diameter Thread per inch Pitch diameter Minor diameter male thread; 1/2: 0.5000: 12: 0.4467: 0.3933: 9/16: 0.5626: 12

BSF (British Standard Fine) Thread Data. Since 1908 this thread, in conjunction with BSW (British Standard Whitworth) has been the mainstay of British Engineering, and was used when finer pitches were required. Angle of thread = 55° British Standard Fine (BSF)

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 ...

  British Standard Whitworth - British Fine Tap and Die Set   This kit contains only the every day taps and dies used on most autos. Most British cars use a combination of BSW and BSF threads, so normally, you would need two tap and die kits,...

U.N.C [national coarse] roughly derived from the British Whitworth having the same pitches except 1/2 in dia where Whitworth is 12tpi and U.N.C is 13 tpi. Both these threads are 60 degree angle. Early Harley and Indian motorcycles used 24tpi threads on most diameters 5/16 and 3/8 UNF are both 24tpi. 7/32 x 24 UNC is an obsolete thread

BA (British Association) Thread Data. This thread has been around for a long time. It was first formulated in 1884 and was standardised in 1903. Mainly found in electrical fittings and accessories, it is slowly being replaced by ISO metric. Angle of thread = 47. 5 degrees, rounded at top and bottom. British Association (BA) 47-1/2 degree thread ...