Alloy steel bar B16 B6 B7 B7M(AISI 4140 4142 4145 4140H) for high tensile bolts
Grade: ASTM A193 B16 B7 B
Mark: Cr-Mo
Size: 12mm-300mm
Application:autopart or high tensile bolts


Chemical composition:
C | Mn | P | S | Si | Cr | Mo | V | Al | |
Chemical composition | 0.36 0.47 | 0.45 0.70 | Max 0.035 | Max 0.040 | 0.15 0.35 | 0.80 1.15 | 0.50 0.65 | 0.25 0.35 | Max 0.015 |
tolerance | +-0.02 | +-0.03 | +-0.005 | +-0.005 | +-0.02 | +-0.05 | +-0.03 | +-0.03 |
Shapes and Dimensions:
Nominal Size(mm) | Cross Section Size(mm) | Length (mm) | Straightness (mm/m) | Corner Angle | Corner Radius (mm) | Ground Roughness Rt(max) |
125-130RCS | 125-130 (+3, -5) | 2800-3000 | Max. 5 | 90°+-2° | 10-25 | 100um |
Length tolerance: +50mm/-0mm
Side length tolerance: +/-2mm
Straightness: Max 3mm/m
Quality Contation
Both end of each bar must be cut.
Ladle furnanced and vacuum de-gassed
Show heat No. on each bar
Surface condition the surface of the hot rolled square bar shall befree cracks, scar and wrinkles that affect the use of the billets. In case there is the above-mentioned defect, it shall be remove.








