Factory Inventory Stainless Steel 304 A2 DIN6921 with Unf Bsf Thread 1/4"-28 Unf X 1" Concave Hex Head Flange Bolt - China Flange Bolt and Full Thread with Teeth Bolt
STEEL ADJUSTER SCREW 1/4 BSF THREAD
Thread data BSW, BSF, BSP 55°; BA Tread Form - Angle of thread = 47. 5 degrees, rounded at top and bottom BA
WHITWORTH AND OTHER BRITISH THREADS | JRC Engineering, Inc.
Helicoil Type Inserts - BSW & BSF Tapped Hole Size Table - Cross Tools Co