... 3.over ten years maker 5.certification: SGS,Rohs din 603 zinc plated grade 8 carriage bolt in hardwarematerial:steel ,stainless ... QuantityQuality AssuranceISO 9001SpecificationDIN603, DIN604, DIN608, ASME B18.5 etc. din 603 zinc plated grade 8 carriage bolt in hardware