... ,zinc SepecificationLong Hex nut (ISO9001 Approve) Materail :carbon steelSize of bolt :M3~M64Thread :half threadCertificate :ISO9001:2008Surface :plain,black,zincHandan HaoSheng ... nut, for example :hex bolt DIN933,hex bolt DIN931,hex nut DIN934,GB5783 bolt,Flange bolt, BSW 916Hex Nuts,Flange nut,round nut,lock nut etc ...