SAE8620

SAE 8620 Alloy Steel Product Overview

SAE 8620 is a low-alloy, case-hardening steel known for its excellent combination of strength, toughness, and wear resistance after carburising and hardening. This nickel-chromium-molybdenum steel, standardised under SAE J404 and ASTM A29, is designed for applications requiring a hard, wear-resistant surface and a tough, ductile core. Its low carbon content ensures good weldability and machinability in the annealed condition, while the alloying elements enhance hardenability and strength. Typically supplied in the annealed or normalised condition (max 229 HB), SAE 8620 is widely used in applications demanding high surface durability and core toughness.

Applications

SAE 8620 is primarily used in case-hardened components for automotive, industrial, and machinery applications:

Automotive:

• Gears, pinions, and gear shafts for transmissions and differentials.
• Camshafts, crankshafts, and connecting rods.
• Axle shafts and steering components.

Industrial:

• Heavy-duty bushings, bearings, and kingpins.
• Sprockets, spline shafts, and clutch components.
• Forged components like couplings and drive shafts.

Other Uses:

• Machine tool parts, such as spindles and arbours.
• Components for agricultural machinery and construction equipment.
• Oil and gas industry parts requiring high wear resistance and toughness.

Chemical Composition

The chemical composition of SAE 8620 provides its case-hardening properties and core toughness:

• Nickel (Ni): Enhances toughness and core strength.
• Chromium (Cr): Improves hardenability and wear resistance of the case.
• Molybdenum (Mo): Increases strength and resistance to tempering.
• Manganese (Mn): Contributes to hardenability and strength.
• Carbon (C): Low content ensures weldability and core toughness, with carburising adding surface hardness.

Supply Size

SAE 8620 is available in various forms and sizes to meet industrial requirements:

• Round Bars:
  Diameter 16 mm to 700 mm.
• Flat Bars:
  Minimum: 10 mm thickness x 80 mm width.
  Maximum: 500 mm thickness x 2000 mm width.