4130 steel commonly referred to as chromoly is a chrome alloy steel with medium carbon content containing .80 – 1.10% chromium as the strengthening agent. 4130 sheet is readily machinable has excellent weldability and offers excellent ductility. 4130 steel sheet is considerably stronger and harder than other standard steel grades and is commonly used in construction of commercial and military aircraft.

TW stocks a wide range of sizes in 4130 steel certified to AMS 6350/6351 – annealed and AMS 6345 for normalized or otherwise heat treated.    

Chemical Composition of 4130 Steel

One big advantage 4130 has over other steels is that it is more corrosion-resistant. This is due to its high chromium content. Additional advantages of using 4130 steel over other steels are:

1. It is dimensionally stable at high temperatures

2. Has a high strength-to-weight ratio

3. Has a high elastic modulus

4. Has low carbon content which makes it easy to weld

4130 steel is most prominently used for structural applications. However, with heat treatment, the steel becomes exceptionally tough and exhibits great workability and machinability. These characteristics mean that 4130 steel is also used in applications such as: mills and cutters, drill bits and taps, bearings, landing gear for aircraft, and mounts for aircraft engines. 4130 steel is known as steel with high corrosion resistance, a high strength-to-weight ratio, and good machinability and weldability. Due to these properties, 4130 is used in aircraft and automotive construction, structural frames, and fasteners for ships, bridges, and buildings. 

Construction/Indutry/Building/Chemical/Auto

Commercial aircraft

Military Aircraft

Automotive

Machine tools

Hydraulic tools

Auto racing

Aerospace