... : 28-150mm grade: 20#, 45#, Q235, 40Cr,27SiMn, 37Mn5,ect. steel round bar size: 28-150mm grade: 20#, 45#, Q235, 40Cr,27SiMn, 37Mn5 ... ,ect. (1) Grade: Round Steel Bar 1045/ 45#/ S45CB(2) Chemical composition %CSiMnCrNiCu0.42-0.500 ... rolled, without heat treatment(8) Application: Free cutting or Forging steel round bar