Bolt, set screw, 1/4in x 5/8in x 26tpi, zinc plated. CEI/ BSCY cycle thread, slightly domed head, Norton AJS matchless Triumph style pre 1960s.Original part numberNorton 8820;12342 - front mudguard stay attachment pin; Bolt attaching jaw joint to saddle frame; tool box frame attachment bolt, topAJS/ Matchless 00-BSA 215662, S5662 - Petrol tank mounting bolt on BSA A50, A65 (1967-70).