ASTM A519 Grade 4130 Chrome Moly Seamless Tube Supplier

Specification Chemical Composition Mechanical Properties

ASTM A519 Grade 4130 Specification

ASTM A519 Seamless Carbon and Alloy Steel Mechanical Tubing In this specification, Grade 4130 is the most common grade of chromium-molybdenum (Cr-Mo) alloy steel, and is equivalent to ASME SA519 4130 for pressure and structural design. The table below shows the main specification requirements of ASTM A519 4130 seamless tube.

Property	Detail
Standard	ASTM A519
ASME Equivalent	ASME SA519 4130
Grade / UNS Number	4130 / G41300
Common Name	Chrome Moly, Chromoly, CrMo 4130
Alloy System	Chromium-Molybdenum (Cr-Mo)
Tube Form	Seamless Mechanical Tubing
Manufacturing Method	Cold Drawn Seamless (CDS) or Hot Finished Seamless (HFS)
Supply Conditions	As-Drawn, Normalised, Annealed, Quenched and Tempered (Q+T)
Relevant Cross-Specifications	AMS 6371, MIL-T-6736, BS 6323 Part 4 CFS 4
Primary Industries	Aerospace, Motorsport, Oil and Gas, Defense, Hydraulics

Mills supplying ASTM A519 4130 seamless tube to aerospace end-users typically also certify to AMS 6371 or MIL-T-6736, which impose tighter dimensional and mechanical tolerances than the base ASTM A519 standard. Confirm the applicable certification level at the time of enquiry.

Chemical Composition of 4130 Chromoly Seamless Tube

The chemical composition of ASTM A519 Grade 4130 is governed by its AISI/SAE 4130 and UNS G41300 designation. The alloy's chromium and molybdenum additions provide deep hardenability and elevated-temperature strength, while the tightly controlled carbon range of 0.28 to 0.33 percent ensures consistent weldability across all wall thicknesses. This low carbon ceiling is the primary reason 4130 maintains its weldability advantage over higher-carbon chromoly grades.

Element	Symbol	% Range	Role in Alloy
Carbon	C	0.28 to 0.33	Controls strength and hardness; kept low to maintain weldability
Manganese	Mn	0.40 to 0.60	Improves hardenability and tensile strength
Silicon	Si	0.15 to 0.35	Deoxidiser; contributes to strength
Chromium	Cr	0.80 to 1.10	Enhances hardenability, corrosion resistance, and high-temperature strength
Molybdenum	Mo	0.15 to 0.25	Improves creep resistance and hardenability in thick sections
Phosphorus	P	0.035 max	Residual element; controlled for toughness
Sulfur	S	0.040 max	Residual element; controlled for weldability

The carbon equivalent (CE) for 4130, calculated using the International Institute of Welding (IIW) formula, typically falls in the range of 0.55 to 0.65. This places 4130 in the 'weldable with precautions' category, where preheat requirements scale with wall thickness rather than being mandatory for all sections.

Mechanical Properties of 4130 Seamless Tube

ASTM A519 4130 seamless tube is available in multiple supply conditions, each producing distinct mechanical property profiles. All strength values are shown in both MPa and ksi to support metric and imperial design codes simultaneously. Values below are representative typical properties; confirm with the relevant mill test certificate (EN 10204 3.1 or 3.2) for each supply.

Condition	Yield MPa	Yield ksi	UTS MPa	UTS ksi	Elong. %	RA %	Hardness
Normalised	620	90	760	110	22	12	163 HB
Annealed	380	55	560	81	28	18	156 HB
Q+T (870 C / 480 C)	655	95	725	105	20	10	22 HRC
As-Drawn (CDS)	517	75	690	100	17	10	207 HB max

Quenched and Tempered (Q+T) 4130 at a tempering temperature of 480 deg C (900 deg F) yields the optimum combination of strength, ductility, and toughness for aerospace and motorsport applications. Tempering at lower temperatures increases hardness but reduces impact resistance. Normalised condition is the most common stock condition for structural tubing and roll cage applications.

4130 vs 4140 Seamless Tube Comparison

Engineers frequently evaluate ASTM A519 4130 chrome moly tube against Grade 4140 for structural and mechanical applications. Both grades are chromium-molybdenum alloy steels within the ASTM A519 specification, but their carbon content difference of approximately 0.10 percent creates significant divergence in weldability, preheat requirements, and achievable hardness. The table below provides a direct comparison of all key parameters to support material selection decisions. For applications requiring maximum hardenability and strength in sections above 50 mm, see AISI 4140 Tubes and Pipes for full grade details.

In summary: 4130 is the correct choice when weldability, weight reduction, and certification to aerospace standards (AMS 6371) are primary requirements. Grade 4140 is the correct choice when maximum core hardness, deeper case depth after heat treatment, or high-cycle fatigue resistance in large cross-sections takes priority over ease of welding.

Applications of 4130 Seamless Tube

ASTM A519 4130 chrome moly seamless tube is the material of choice across aerospace, motorsport, defense, and oil and gas industries. Its chromium-molybdenum chemistry delivers tensile strength levels of 725 MPa (105 ksi) in Q+T condition at a density of 7.85 g/cm3, giving one of the highest strength-to-weight ratios of any carbon steel tubing grade.

Aerospace Structural Tubing

• Aircraft fuselage structural tubes, longerons, and struts
• Wing spar supports and engine mount structures
• Airframe weldments certified to AMS 6371 and MIL-T-6736
• Hydraulic actuator tubes and fluid power lines
• Helicopter skid tube assemblies

Motorsport and Automotive Applications

• FIA-homologated roll cage and space frame construction (CDS 4130 normalised)
• Formula and sports car chassis tubes and suspension pick-up points
• Rally car safety cage tubes to FIA Technical List No. 25
• Motorcycle frame tubes and swingarm structures
• Drag racing chassis and axle housing fabrication

Oil, Gas, and Industrial Applications

• Drill collar tubing and downhole tool bodies
• Hydraulic cylinder barrels and precision bore tubes
• High-pressure fluid transmission lines
• Defense ordnance and armament structural components

Where project specifications permit the use of carbon steel tubing and elevated strength is not required,ASTM A519 1045 Seamless Tube provides a cost-effective alternative for non-aerospace structural and mechanical applications.

Supply Conditions and Dimensional Availability of 4130 Chromoly Tube

ASTM A519 4130 seamless tube is available in a wide dimensional range to support both small-bore precision applications and heavy-section structural fabrications. All supply conditions are stocked or available on short lead times. Dual-certified material to both ASTM A519 and AMS 6371 is available on request for aerospace programs.

Tolerances and Quality Documents

Standard dimensional tolerances follow ASTM A519 Table 1 (OD and wall tolerance). Closer tolerances to ASTM A519 Class 1 or AMS 6371 are available on order. All material is supplied with full material test reports (MTRs) to EN 10204 3.1 as standard. Third-party witnessed 3.2 certificates are available on request. NACE MR0175 compliance documentation is available for sour service oil and gas applications.

Other ASTM A519 Seamless Mechanical Tubing Grades

ASTM A519 4130 seamless tube is one of eight grades within the A519 grade cluster. The full grade index is listed below. Each grade page includes its own chemical composition table, mechanical property matrix, and application guide. All pages link back to the ASTM A519 Seamless Mechanical Tubing parent hub.

Related Products

• ASTM A519 Seamless Mechanical Tubing
• Alloy Steel Pipes and Tubes
• Alloy Steel Seamless Pipes and Tubes
• Cold Drawn Seamless Mechanical Tubing
• Hot Finished Seamless Mechanical Tubing

Related Keywords

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