Whitworth Threads

Whitworth Threads

Whitworth threads are a type of screw thread that was developed by Joseph Whitworth in 1841. Whitworth threads are characterized by a 55-degree thread angle and a square root of 3 (1.73205) pitch. Whitworth threads were the first standardised screw thread system in the world, and they are still widely used in the United Kingdom and other countries that use the imperial system of measurement.

History of Whitworth Threads

Before the development of Whitworth threads, there were many different types of screw thread systems in use. This made it difficult to manufacture and assemble parts, as it was often necessary to use custom-made tools. Whitworth's design was a significant improvement over previous systems, as it was both strong and easy to manufacture.

Whitworth threads were quickly adopted by the British engineering industry, and they soon became the standard for screw threads in the United Kingdom. In 1881, the British government adopted Whitworth threads as the official standard for screw threads in the country.

Where and Why Whitworth Threads are Used

Whitworth threads are still widely used in the United Kingdom and other countries that use the imperial system of measurement. They are also used in some applications in the United States, such as in the aerospace industry.

Whitworth threads are used for a variety of reasons. They are strong, durable, and easy to manufacture. They are also compatible with other Whitworth threads, which makes them ideal for assembly.

Specific Standards Where Whitworth Threads are Defined

There are a number of standards that define Whitworth threads. The most common standard is BS 84:1956. This standard defines the geometry and dimensions of Whitworth threads.

Internal Whitworth Threads

Internal Whitworth threads are threads that are cut into the interior of a part. These threads are commonly used in nuts. Internal Whitworth threads are typically identified by the letter W followed by the major diameter of the thread in inches. For example, an internal Whitworth thread with a major diameter of 1/2 inch would be identified as W1/2.

Conclusion

Whitworth threads are a versatile type of screw thread that is used in a wide variety of applications. They are strong, durable, and easy to manufacture. Whitworth threads are also compatible with other Whitworth threads, which makes them ideal for assembly.

BSW and BSF Threads

BSW and BSF are two types of Whitworth threads that are commonly used in the United Kingdom. BSW stands for British Standard Whitworth, and BSF stands for British Standard Fine Whitworth.

BSW threads have a coarse pitch, while BSF threads have a fine pitch. BSW threads are typically used for applications where strength is more important than accuracy, while BSF threads are typically used for applications where accuracy is more important than strength.

Whitform

Whitform is a type of Whitworth thread that is designed to be stronger than standard Whitworth threads. Whitform threads have a sharper thread angle (60 degrees) and a larger root radius than standard Whitworth threads.

Whitform threads are typically used in applications where high strength is required, such as in the aerospace industry.