ASTM A519. It covers several grades of steel, with Grade 4130 being one of the most popular.
In simple terms, when you see "ASTM A519 4130," it refers to a seamless tube made from chromium-molybdenum alloy steel (4130) that is manufactured to meet the mechanical property requirements of the A519 standard.
1. Key Characteristics of SAE/AISI 4130 Steel
The material itself, 4130, defines its chemical composition and inherent properties.
Chromoly Steel (Chrome-Moly)
0.28-0.33% (Provides strength and hardenability)
0.80-1.10% (Increases hardenability, corrosion resistance, and strength at high temperatures)
0.15-0.25% (Enhances strength at high temperatures and improves hardenability)
High Strength-to-Weight Ratio: Stronger than mild steel (e.g., ASTM A513) without a significant weight penalty.
Can be formed and machined relatively well in the normalized or annealed condition.
Welds well with proper procedures (pre-heating and post-weld heat treatment are often recommended, especially for thicker sections).
Its properties can be precisely tailored through processes like quenching and tempering to achieve specific strength, hardness, and toughness levels.
2. Requirements of ASTM A519 Standard
The A519 standard specifies the requirements that the finished seamless tube must meet, primarily focusing on . The key point is that A519 is a spec, not just a chemical spec.
(heat treatment) of the tube. The most common conditions are:
| Typical Mechanical Properties (Minimum) for 4130 | ||
|---|---|---|
| Grade 1020 (for comparison) | Tensile: 70 ksi (483 MPa) Yield: 50 ksi (345 MPa) | |
| 4130 - Annealed | Tensile: 75 ksi (517 MPa) Yield: 45 ksi (310 MPa) | |
| 4130 - Normalized | Heated and air-cooled for uniformity | Tensile: 80 ksi (552 MPa) Yield: 50 ksi (345 MPa) |
| 4130 - Normalized & Tempered | Tensile: 90 ksi (621 MPa) Yield: 60 ksi (414 MPa) | |
| 4130 - Quenched & Tempered | Tensile: 95-110 ksi (655-758 MPa) Yield: 75-85 ksi (517-586 MPa) |
Other A519 Requirements:
Covers outside diameter (OD) and wall thickness (WT) tolerances.
The tube must be commercially smooth and free of defects that would be harmful to its intended application.
While not always mandatory, eddy current or ultrasonic testing can be specified to ensure internal and external soundness.
3. Common Applications
ASTM A519 4130 seamless tubing is chosen for applications requiring high strength, reliability, and a good strength-to-weight ratio.
Hydraulic lines, structural components, landing gear parts.
Roll cages, chassis components, drive shafts, suspension parts.
Downhole tools, instrumentation tubing, hydraulic cylinders.
High-pressure hydraulic cylinders, piston rods, bearing sleeves, and other high-stress mechanical components.
4. Comparison with Other Common Standards
It's important to distinguish A519 from other standards that also cover 4130 steel.
| ASTM A519 | . Used for structural and mechanical parts. | |
| ASTM A29 | 4130 is commonly supplied as bar stock under this standard. A519 is specifically for tubular products. | |
| AMS 6370 | Aerospace Material Specification for 4130 Steel Tubing | A more stringent version for aerospace, with tighter controls on chemistry, grain size, and quality. |
| ASTM A513 | Electric-Resistance-Welded Carbon and Alloy Steel Mechanical Tubing | tubing. A519 is exclusively for tubing, which is generally stronger and more reliable for high-pressure applications. |
ASTM A519.
Grade 4130chromium-molybdenum alloy steel.
ASTM A519 4130 specifies a high-strength, seamless tube with guaranteed mechanical properties, making it ideal for critical applications in aerospace, automotive, and heavy machinery.
When ordering, you would typically specify the standard (ASTM A519), the grade (4130), the dimensions (OD and WT), the length, and the required heat treatment condition (e.g., Normalized & Tempered).
