Aircraft Alloy Steel AISI 4140 (AMS 6349/ AMS 6382)

Technical Data Sheet

Alloy 4140 (AISI 4140) is a low alloy steel containing Chromium and Molybdenum. Alloy 4140 is the most widely used alloy for oil patch applications. Usually supplied hardened and tempered to condition T in sections up to 100mm with a tensile strength of 850 - 1000MPa and aiming for this strength range in larger sections. Alloy 4140 (AISI 4140) offers a very good balance of strength, toughness and wear resistance. Other typical applications are axles, conveyor parts, crow bars, gears, logging parts, spindles, shafts, pump shafts, sprockets, studs, pinions, rams, ring gears.

Typical Mechanical Properties

Availability

Alloy 4140 (AISI 4140) is available in Bars (Rounds, Flat, Square, Hexagons), Powder.  For all stock availability contact Sales.

NEW - Aircraft Materials now offers a comprehensive range of high-quality Alloy 4140 metal powders, produced and tested to exacting standards for use in all processes including Additive Manufacturing (AM), Near-Net Shape Powder Metallurgy (NNS/PS) and Hot-Isostatic Pressing (HIP).

Specifications

AMS 6349

AMS 6382

AMS S 5626

MIL S 5626

AS 1444-1996

UNS G41400

Heat Treatments

4140 Forging:

Heat to 1150°C Hold until uniform. Minimum forging temperature 850°C. Cool slowly in ashes or sand etc.

4140 Annealing:

Heat to 830°C-850°C. Cool in furnace

4140 Normalising:

Heat to 870°C-900°C

Cool in still air

4140 Stress Relieving:

Annealed: Heat to 600°C - 650°C

Hardened: Heat to 500°C - 550°C

4140 Hardening:

Heat to 830°C- 800°C

Quench in oil or polymer

4140 Tempering:

Heat to 450°C-700°C cool in still air

NB Tempering within the range 200°C - 420°C will result in temper brittleness and should be avoided