Alloy Grade UNS: SC 4340 – General Structural Use

  • Overview

    J24053 is a general structural-use alloy. It has high tensile strength and abrasion resistance, especially after heat treated. It also has good weldability, castability, and machinability. Also known as SC 4340, this alloy is typically used for marine propulsion parts.

  • Typical Uses

    Cylinders, marine propulsion, rolls, and shaft sleeves.

  • MetalTek Grade

    MTEK 4340

Similar Specifications

Cast UNS: J24053

Wrought UNS: G43400

Wrought Grade: AISI 4340

Cast Grade: SC 4340

Cast ASTM: A915, A732

Military/AMS: AMS 5331

Typical Chemical Composition (% by wt.)

Aluminum: n/a

Carbon: 0.4

Chromium: 0.8

Manganese: 1 MAX

Iron: BAL

Copper: n/a

Nickel: 1.8

Lead: n/a

Tin: n/a

Silicon: 0.60 MAX

Zinc: n/a

Other: Mo 0.30

Minimum Mechanical Properties

Tensile, ksi


Tensile, MPa


Yield, ksi


Yield, MPa




Heat Treatment: Normalize, Quench And Temper