4BA x 1 inch Cheese Head Screws (BS 57 : 1951) - Stainless Steel (A2)
Fastenerdata - BA Threads British Association 200-c - Fastener Specifications
Threading Tables-Whitworth, BSF, etc
Bonehill hammers and screws questions - The DoubleGun BBS @ doublegunshop.com
4BA Socket Cap Screw High Tensile 12.9 DIN912 – Fixaball Ltd. Fixings and Fasteners UK
Fastenerdata - BA Threads British Association 200-c - Fastener Specifications
M thread (metric ISO-thread) | Determination – Thread Types | Screw Joints | Technical information | BOLA - Tubing, Stirrer Shafts, Magnetic Stirring Bars - Labware made of PTFE
British Association Screw Threads | BA Thread Chart | Apollo International
Recoil British Thread & 8 TPI Tapped Hole and ... - Maryland Metrics