British Standard Thread Handbook摘要：British Standard Thread Handbook Introduction British Standard Threads (BST) are the most commonly used threads in the UK and many other countries. They were es
Introduction
British Standard Threads (BST) are the most commonly used threads in the UK and many other countries. They were established by the British Standards Institution (BSI) and are commonly referred to as Whitworth threads after their creator, Joseph Whitworth. BSTs are used in a variety of applications ranging from plumbing and gas fittings to machinery and automotive parts.
Types of British Standard Threads
There are two main types of BSTs: the Whitworth thread and the British Standard Pipe thread (BSP). The Whitworth thread, also known as the British Standard Fine (BSF) thread, is a cylindrical thread with a 55-degree thread angle and a rounded crest and root. It is used in applications where high torque is required, such as in automotive and machinery parts. The BSP thread, on the other hand, is used in pipe fittings and has a tapered thread with a 60-degree angle.
Dimensions of British Standard Threads
The dimensions of BSTs are specified in the BSI standard BS 3643. This standard specifies the thread form, thread sizes, thread pitch, and other important parameters. The thread sizes are specified in terms of the nominal diameter of the thread, which is the diameter of the imaginary cylinder that just touches the crest of the threads. For example, a 1/2\" BST has a nominal diameter of 0.5 inches. The thread pitch is the distance between adjacent threads, and it is specified in threads per inch (TPI) for Whitworth threads and millimeters for BSP threads.
Conclusion
British Standard Threads are widely used in the UK and many other countries due to their high torque capability and versatility. Understanding the different types and dimensions of BSTs is important for selecting the right thread for a particular application. The BSI standard BS 3643 provides detailed specifications for BSTs that should be followed for ensuring compatibility and reliability.
