Sometimes the symbol “BSCy” is used. This series replaced the Cycle Engineers' Institute (CEI) thread. Though the two series are somewhat different, in the early 21st century the BSC series was still sometimes being called the CEI series. For an even earlier thread, see the bottom of the BSW page.
Symmetrical 60° thread angle, with rounded roots and crests having a radius of 0.166 times the pitch. Actual depth, 0.5327 times the pitch. The smaller sizes are for spokes.
|Tap Drill Size|
|1.370||24||1 21/64 inch|
British Standard 811-1938. British Standard Cycle (B.S.C.) Threads.
Fasteners with these threads can be obtained from:
Copyright © 2006 Sizes, Inc. All rights reserved.
Last revised: 16 September 2006.