What is Grade 4130?

Grade 4130 is a low-alloy chromium-molybdenum steel with an excellent strength-to-weight ratio. This 4130 chromoly tube is used in aerospace, automotive racing, and structural applications where weight savings are critical. The alloy responds well to heat treatment and maintains good toughness, making it the standard choice for aircraft structures and high-performance chassis components.

ASTM A519 Grade 4130 Tube Specification

Technical specifications for ASTM A519 Grade 4130 chromoly tubing are as follows:

ASTM A519 Grade 4130 Tube Chemical Composition

The table given below highlights the chemical composition of AISI 4130 steel tube in accordance with the ASTM A519 standard.

Ni C Mo Mn Si Fe Cu S P Cr
AISI 4130 0.50 max 0.28-0.33 0.15-0.25 0.40-0.60 0.15-0.35 97.3-98.22 – 0.025 MAX 0.035 MAX 0.80-1.10

ASTM A519 Grade 4130 Tube Mechanical Properties

To evaluate material performance for structural and aerospace applications, refer to the mechanical properties detailed below for 4130 chromoly steel tubing:

Density Melting Point Yield Strength (0.2% Offset) Tensile Strength Elongation
0.28 2580 460 MPa 560 MPa 20 %

ASTM A519 Grade 4130 Tube Equivalent Grades

The following table presents AISI 4130 chromoly steel equivalents across major international standards:

STANDARD UNS WERKSTOFF NR. AFNOR EN JIS BS GOST
AISI 4130 G41300 1.7218 – 25CrMo4 JIS G4105 BS 970 –

4130 vs 4140

AISI 4130 and 4140 are both chrome-molybdenum alloys with distinct characteristics suited to different applications, as compared below:

  • 4130: Lower carbon (0.28-0.33%), better weldability, preferred for aerospace structures
  • 4140: Higher carbon (0.38-0.43%), higher strength, used for high-strength applications

Select 4130 when weldability is critical; choose 4140 when maximum strength is required.

Applications

The 4130 chromoly round steel tube serves weight-critical structural applications:

Aerospace

Aircraft structures, landing gear components, and airframe tubing use 4130 alloy steel tube for its high strength-to-weight ratio and excellent weldability.

Racing

Roll cages, chassis tubes, and structural components in motorsport applications rely on 4130 chromoly tubing for its combination of strength, light weight, and crashworthiness.