SAE 4140 Alloy Seamless Steel Pipe Custom 6m 8m 10m Length 42CrMo4 Alloy Steel

4140 steel (or AISI 4140 steel as it is called in the USA) is a widely used metal due to its resistance to corrosion and other favorable properties. This article discusses 4140 steel in detail, its properties and uses in mechanical industries, and how to weld this alloy metal.

AISI SAE 4140 low-alloy steel containing chromium and molybdenum is widely used in general purpose high tensile steel for components like axles, shafts, bolts, gears, collars, and a wide variety of applications across the engineering and automotive industries.

AISI SAE 4140 low-alloy steel containing chromium and molybdenum is widely used in general purpose high tensile steel for components like axles, shafts, bolts, gears, collars, and a wide variety of applications across the engineering and automotive industries.

4140 Steel and its Properties

4140 steel is a low alloy with chromium and molybdenum as strengthening agents. This steel also contains carbon, manganese, and other elements. The chromium in 4140 steel imparts superior hardness penetration, manganese improves its hardenability, and molybdenum makes it strong (tough).

Chromium and molybdenum make 4140 a better corrosion-resistant steel than ordinary alloy steels, making it a great choice for products exposed to harsh environments. Manganese and sulfur content in 4140 steel enhance its machinability.

The 4140 steel has good toughness, high strength, ductility, wear resistance, and a good strength-to-weight ratio. It has high fatigue strength, torsional strength, and good abrasion and impact resistance.

4140 steel is available in bars (different sections like round, hexagon, square, etc.), sheets, and other sections. It is available in the form of cold rolled rounds with added lead (a small quantity of 0.15 to 0.35%) to improve its machinability (however, this is not recommended for welding applications (welding fumes are not healthy) and any applications that involve heating above 400° F).