3/8" Thread Standards

For every Rycote product which gets attached to a boom pole or mic stand, there is a female 3/8" thread.

The accepted standard of thread for all boom poles is the 3/8" British Standard Whitworth (BSW), with 16 teeth per inch (TPI); however, the close similarity to another thread standard, UNC, has meant that some manufacturers are now producing 3/8" 16 UNC on their poles & stands rather than 3/8" Whitworth.

The difference between the two threads is very small -- a matter of 5°, in fact -- but it has significant implications for fitting the two thread types together. Put simply, they won't fit. As you can see in the attached drawing (see end of article), the BSW has a thread angle of 55° and the UNC 60°; so a male BSW will fit into both BSW & UNC, but a male UNC will not fit into the industry standard BSW.

To prevent this causing compatibility issues, Rycote has manufactured all of its threads since 2003 using the following standards:

- Female 3/8" UNC (Brass)

- Male 3/8" BSW (Stainless steel)

This means that all Rycote products -- whether female or male threaded -- will fit together with other accessories using 3/8" threads.

If you have any questions about this, or any of our other products please don't hesitate to let us know.