Long Hex Nuts(ISO9001 Approve) Grade :4.8,5.8,6. ... ,zinc SepecificationLong Hex nut (ISO9001 Approve) Materail :carbon steelSize of bolt :M3~M64Thread :half threadCertificate :ISO9001:2008Surface :plain,black,zincHandan HaoSheng ... bolt and nut, for example :hex bolt DIN933,hex bolt DIN931,hex nut DIN934,GB5783 bolt,Flange bolt, BSW 916Hex Nuts,Flange nut,round nut,lock ...