Specification                  Standard            Grade
50*37*4.5--400*104*14.5       GB(China) Q235A\B etc.
75*40*3.8--250*90*9           JIS                  SS400 etc.
177*54*5.3--305*80*13          ASTM Cr.D etc.
80*45*6--200*75*8.5           DIN                  S235  JR etc.