What is BSW Thread
Sir Joseph Whitworth developed this thread in 1841 in the UK, considered the first standardized thread shape. The main feature of the British Standard Whitworth thread shape is that the angle between the flanks of the thread and the radius between the root and the crest is 55 degrees. Whitworth thread shapes are not commonly used for nuts and bolts, as they have been replaced by unified and metric thread series. However, the Whitworth thread shape remains the standard for pipeline components in the European Community.
B.S.W. Thread Sizes Chart
BSW (British Standard Whitworth):
Coarse thread with a 55-degree flank angle.
It is typically used for general-purpose applications and offers better strength and grip.
B.S.F. Thread Sizes Chart
BSF (British Standard Fine):
Fine thread has a 55-degree flank angle but a smaller pitch than BSW.
Used where a finer adjustment is necessary, such as in precision applications or where space is limited.
British Standard Whitworth Thread Shape
The British Standard Whitworth thread profile includes several thread series:
British Standard Whitworth (BSW), defined in BS 84. (BS 84 PDF)
British Standard Fine (BSF), which has a finer pitch than BSW, is also defined in BS 84.
British Standard Pipe Taper (BSPT), now called the R series, is defined in ISO 7, EN 10226, BS 21, and former DIN 2999.
British Standard Parallel Pipe (BSPP), now referred to as the G series, is defined in ISO 228 and former BS 2779.
Coarse thread series (B.S.W.) – Basic sizes
Fine thread series (B.S.F.) – Basic sizes
More information:
