ASTM A653M standard?

Question

1). What's difference with ASTM A653 & ASTM A653M?

2). In ASTM A653 CS Type A, B, C, waht's difference with CS type A,B,C?

Answer 1

ASTM A653 / A653M - 07 Standard Specification for Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) by the Hot-Dip Process

The M typically is for Metric.  A653 the differences are probably in the standard, for various types of galvanizing (galvanizing is one and galvannealed is the second and some other kind is the type C..

You'd have to get the standard to be certain.

try www.galvanizeit.org.