high tensile bolts and nuts: 1Used for steel structures 2We can produce by customer's drawings. 3Certificate:ISO9001:2008,SGS Tortous type high tensile bolts and nuts washers for steel structures 10.9 >> We manufacture ASTM E1852 & GB/T 3632 series standard products as customer demand. >> Apply to railway, highway, bridge, boiler with steel structure,industry workshop,high civil buildings, ...