Spanner sizes: M8 = 13MM. A2 STAINLESS STEEL HEXAGON HEAD SET SCREW BOLTS FULLY THREADED & PART THREAD. Bolts are fully threaded Or Part Threaded. Stainless Steel A2 (304), DIN 933 & DIN931. Manufactured from A2 Stainless Steel For Improved Corrosion Resistance.