4140 Steel
SAE 4140 is a versatile chromium-molybdenum alloy steel known for its strong combination of high strength, toughness, and wear resistance. This grade is often selected for components that must perform under high stress, cyclic loading, or elevated temperature conditions.
grades designations
SAE 4140 is an alloyed steel furnished to defined chemical composition. The typical chemical composition includes approximately 0.38–0.43% carbon, 0.15–0.35% silicon, 0.75–1.00% manganese, 0.80–1.10% chromium and 0.15–0.25% molybdenum, with phosphorus and sulfur limited to low levels.
4140 Characteristics
Property
specification
Weldability
SAE 4140 maintains good weldability for an alloyed steel when proper practices are followed.
Thermal Cutting
Careful control of heat input and edge cooling is necessary to avoid localized hardening or microstructural change that can impair toughness or cause cracking.
Bendability
In the annealed or normalized condition, AISI 4140 exhibits reasonable formability and bendability for fabrication operations.
Hardness
The hardness of 4140 varies by heat treatment condition.
