Round steel is categorized into three types: hot rolled, forged, and cold drawn. Hot-rolled round steel specifications range from 5.5-250mm. Small round steel bars (5.5-25mm) are typically supplied as straight bars and commonly used as steel reinforcement, bolts, and various mechanical components. Round steel larger than 25mm is primarily utilized in manufacturing mechanical parts and seamless steel pipe billets.
| Category | Grades | Diameter | Standard |
|---|---|---|---|
| Carbon Structure Steel | Q195, Q215, Q235, Q275 | 10mm-600mm | GB/T700-2006 |
| Low Alloy High Strength Structure Steel | Q295, Q345, Q390, Q420, Q460 | 10mm-600mm | GB/T1591-2008 |
| Prime Carbon Structure Steel | 10#, 20#, 35#, 45#, 60#, 20Mn, 65Mn, B2, B3, JM20, SH45, S45C, C45 | 10mm-600mm | GB/T699-1999 |
| Alloy Structure Steel | 30Mn2, 40Mn2, 27SiMn, 42Crmo, 20Cr, 40Cr, 20CrMo, 35CrMo, 20CrMnTi, 30CrMnTi, 20MnVB, 20MnTiB, 20CrNiMo, Q345B, 35MnBM, 40MnB, 36Mn2V, 45MnV | 10mm-600mm | GB/T3077-1999 |
| Spring Steel | 65Mn, 60Si2Mn, 50CrVA | 10mm-600mm | GB/T1222-84 |
| Bearing Steel | GCr15, GCr15GD, 55SiMoV | 10mm-600mm | GB/T18254-2002 |
| Structural Steels Subject to End-Quench Hardenability Requirements | 20CrMnTi, 30CrMnTi, 20Cr, 40Cr, 30CrMo, 42CrMoA, 27SiMn, 40Mn2H, 20CrNiMo, 40Mn2, q345b, 35MnBM, 40MnB, 45MnV | 10mm-600mm | GB/T5216-2004 |
| Oil Wells Structural Steel | 37Mn5, 36Mn2V | 10mm-600mm | Q/LYS248-2007 |
| Marine Anchor Chain Steel | CM490, CM690, M30Mn2 | 10mm-600mm | YB/T66-1987 GB/T18669-2002 |