UNF A2 Grade Stainless Steel Half Lock Nuts Thread - UNF Grade - A2 Stainless steel Type -Half lock jam nuts. ABCD 1/4" 0.4291 0.1535 28 5/16" 0.4921 0.1771 24 3/8" 0.5511 0.2086 24 7/16" 0.6771 0.2440 20 1/2" 0.7362 0.3110 20 5/8" 0.9251 0... £0.24 (Inc. VAT) £0.20 (Ex. VAT) Choose Options Compare