Which statement accurately describes the British Standard Cycle (B.S.C.) thread?

• A. It is a British imperial screw thread standard with a 60-degree thread angle.
• B. It is a metric screw thread standard with a 60-degree angle.
• C. It is a British imperial pipe thread standard.
• D. It is a square thread form used for high-load applications.

Answer: (A)

At its core, the British Standard Cycle thread is a screw-thread standard used in British bicycle components, defined in imperial units and with a 60-degree thread angle. This combination sets it apart from metric threads (which use millimeter sizing) and from pipe threads (which belong to a different standard with a distinct purpose and often different angle). It also isn’t a square-thread form, which is a different profile used for power screws. So the statement describing it as a British imperial screw thread standard with a 60-degree angle matches how BSC threads are defined and used.