Professional provides: 
 A: 12.9 hex bolts, hex bolts 10.9 and ASTM high strength bolts (strength bolts HSB), Material: SCM435 SCM440 and A325 | A490 | A449. 
 For wind power generation and construction industries. 10.9 hex bolts | 12.9 级 hex bolts | A325 | A490 | A449 | ASTM bolt 

 ASTM bolt of the application: 
 A: A325 bolt TYPE1 in the amount of carbon, carbon boron, or carbon steel for general steel, hot dip galvanized. 
 A325 bolts TYPE2 1991/11 onwards disabled. 
 A325 bolts TYPE3 weathering steel, corrosion resistance of weathering steel is equivalent to A242/A566/A709 so suitable for the steel used in conjunction with the weather. 
 Can be hot-dip galvanized. 
 Two: A490 bolts TYPE1 to alloy steel bolts, the nominal diameter of 1 / 2 "to 1 1 / 2" for general steel, not galvanized. 
 TYPE2 bolts A490 bolts are usually made of low carbon martensite Steel, the nominal diameter of 1 / 2 "to 1 1 / 2", can not be hot-dip galvanizing. 
 A490 bolts TYPE3 weathering steel, corrosion resistance of weathering steel is equivalent to A242/A588/A709 so suitable for use together with weathering steel. Can not be hot dip galvanized 
 Three: A449 bolt TYPE1 in the amount of carbon, the nominal diameter of 1 / 4 "3." Suitable for general steel structure, can be used for high temperature, can be hot-dip galvanized. 
 A449 bolts TYPE2 carbon