Aerotight M6 A2 Grade Stainless Steel Self-Locking Nut Thread Size (Nom) - M6 Pitch - 1.0 mm A/F Max- 10.0 mm N-Dia Max - 9.58 mm H Max - 7.95 mm F Min - 4.63 mm Aerotight self locking nuts are: All metal Stiff nut with no inserts Can be re-used Will stay in position whether tightened down or not No special tools required When assembled on the screw, 2 full threads should protrude through the nut A2 stainless steel has good resistance to corrosion except in severe industrial and Marine Condition. Use A4 in a marine environment.