BS EN ISO 10510 pdf download Tapping screw and washer assemblies with plain washers 1 Scope This International Standard specifies the requirements for tapping screws and plain washer assemblies withthread sizes from ST2,2 to ST9,5 inclusive, flat seating heads and mechanical properties as specified inISO 2702. The plain washers are captive, i.e. prevented from disassembly and free to rotate. 2Normative...