steel flat bar,Sping steel,Standard: GB/T702, JIS G3101, JIS G3193 . machinery ... barSize: 100x14mm,100×30mm,130×30mm,140x16mm,170×20mm,170×22mm,180× 20mm,180×25mm.MaterialQ235B, Q345B, SS400, SS540, St37, St52 ... structure, boilers making ,etc.Advantage: stable spec & accurate dimension flat bar