4140 GRADE ALLOY ROUND BAR

IF YOU CANT SEE YOUR REQUIRED SIZE RING 08 9528 6400 FOR A QUOTE

4140 Grade Alloy Steel is a versatile, medium-carbon chromium-molybdenum (chromoly) high-tensile steel alloy renowned for its exceptional balance of strength, toughness, fatigue resistance, and high wear resistance. It is widely considered the industry standard general-purpose engineering steel for heavy-duty mechanical components.

• Tensile Strength: 655 to 1,170 MPa (95 to 170 ksi)
• Yield Strength: 415 to 950 MPa (60 to 138 ksi)
• Hardness: Typically 197 HBW (Annealed) up to 270–300 HBW (Pre-hardened). It can be surface hardened to over 50 HRC.
• Machinability: Rated at roughly 50–55% of standard 1212 screw stock, meaning it cuts smoothly before full heat treatment

• Chromium (Cr) [0.80% – 1.10%]: Increases hardenability and provides excellent wear and abrasion resistance.
• Molybdenum (Mo) [0.15% – 0.25%]: Refines grain structure, ensures high-temperature strength, and prevents temper brittleness.
• Carbon (C) [0.38% – 0.43%]: Governs core hardness and structural strength.
• Manganese (Mn) [0.75% – 1.00%]: Regulates overall toughness and depth of hardenability.

Peeled and Polished (Bright Bar): Stripped of its mill scale to provide precise dimensional sizing, high surface consistency, and a bright, ready-to-machine finish.

• Drive Shafts and Axles: High fatigue resilience handles heavy rotational loads.
• Industrial Power Gears: Absorbs impact and resists wear under friction.
• High-Tensile Studs, Bolts, and Fasteners: Replaces mild steel when higher shear strength is mandatory.
• Oil and Gas Tooling: Used for downhole tools, tool joints, drill collars, and heavy-duty pins.