... :GB/T 1228-1231,ISO7412,DIN6914-6916,ASME B 18.2.6 (ASTMA325,A490), JISB1186 AS1252Grade: ... tensile strength bolts for rail bridges etc.3, Various type and sizes of tie plates, clamps, fastenings, ... tolerance according to GB/T 3103.1-2002 - b + 2 p the rest of the general tolerance ... 4'' 5.High tensile Description(TC bolt) Torshear type high strength bolts for steel structureMaterialAlloy steel ,carbon ...