Outside the six angle bolt classification: 1, ordinary bolt points A, B,C three. The first two are refined bolts, less used. Generally speaking,ordinary bolts, all of which refer to C grade ordinary bolts.
2 in some temporary connection and the need to remove the connection, commonly used to C grade ordinary bolt. Common bolts used in building structure are M16, M20, M24. Some machinery industry coarse bolt diameter may be relatively large, special purpose.

3, American bolt is divided into common thread and fine thread 2, strength grade is 2, 5, 8 three levels, and stainless steel products, the above metric American, our have large inventories.

ASME hex bolts, are widely used in: environmental protection equipment, medical equipment, communication equipment, electric power facilities, and electronic products, food machinery, petroleum chemical industry, ship assembly, valve and pipeline, building, engineering machinery, automobile industry, ship manufacturing, wind power, hydraulic transmission, injection molding machine, mould, bridge manufacturing a variety of fields. 1-3/4UNF, 1-3/4UNC