1.Specification M20 2.Grade: 8.8 3.Materials :Q235 4.ISO9001:2008 5.Free sample for test . M20 high strength theread railway anchor bolts The bolt is a kind of railway parts, referring to track including rail, sleeper, and connecting parts, ballast bed, prevent climbing equipment, rail brace and switch, etc. As a general engineering structure, track laying on the subgrade, plays a leading role in ...