Hard lock nut 1.Material:Carbon&stainless steel 2.Size:M3-M64 3. ... Finish.Zinc,Nickel plated,Black Oxide,HDG 4.SGS,ISO approve Hard ... lock nut 1. Standard:DIN, ANSI,BSW, JSB ans ISO standard ... ,SS316 A4 etc), Brass or according require.3. Grade of Hard lock nut: Metric standard: Grade 4.8, Grade6.8, ...