nut and bolt: 1Materials:1045/5140/35Cr-Mo 2Surface ... .8,10.9,12.9 Torshear type high strength nut and bolt washer for steel structures I. Specification: GB ... have certified by ISO9001:2008 Quality Management System and got the Production Permission License from the Ministry of ... A., Canada, Cuba, Germany, Japan, Singapore, Malaysia and Africa and so on. Pictures:1.certificates 2.ProductsBolts with nuts ...