Thread data BSW, BSF, BSP 55°; BA Tread Form - Angle of thread = 47. 5 degrees, rounded at top and bottom BA
Helicoil Type Inserts - BSW & BSF Tapped Hole Size Table - Cross Tools Co
1/4-1/2-inch BSF Thread Repair Workshop Kit
1/4" x 26 BSF Tap & Die Set Taper Plug & Die Carbon Steel BSF Thread
British Standard Fine Thread Chart
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