Welcome to USA Piping Solution. When projects demand steel that brings serious strength, toughness, and wear resistance to the table, AISI 4140 Tubes & Pipes are often the go-to choice. We specialize in providing this high-performing low-alloy steel, also known as a type of Chromoly Pipe or tubing. As a major US-based source - manufacturing, supplying, and stocking - we connect extensive global resources with personalized, US-focused service. Delivering reliable Alloy Steel Pipes & Tubes, especially materials meeting ASTM A519 Grade 4140 standards, is a key part of our business. From demanding oilfield tools to high-stress automotive parts and heavy machinery components, many sectors count on 4140's proven durability. Choosing USA Piping Solutions means getting certified materials engineered for high strength in challenging conditions.
We understand that materials destined for heavy-duty work need consistent quality and precise properties. That understanding guides our commitment to the integrity of every 4140 Seamless Pipe and tube we handle. Typically produced using seamless methods for superior structural soundness, AISI 4140 offers excellent fatigue resistance and impact strength, particularly after it's properly heat treated. Need standard sizes, perhaps already quenched and tempered for strength, delivered quickly? Our large inventory likely has what you need. Have specific requirements for custom lengths, tailored heat treatments, or other processing steps? USA Piping Solutions has the expertise and facilities to manage those requests effectively. You can count on us for premium 4140 Mechanical Tubing, fully certified and backed by our knowledgeable support staff and efficient worldwide shipping.
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What Makes AISI 4140 Stand Out?
Let's talk about AISI 4140. This code identifies a very popular and versatile low-alloy steel. Like its close relative, 4130, it's part of the chromium-molybdenum ("Chromoly") group. The main difference between them? Carbon content.
The "41" tells us it's a chromium-molybdenum steel, and the "40" points to a nominal carbon level of about 0.40%. This extra carbon (compared to 4130's ~0.30%) is the key to 4140's ability to achieve much higher strength and hardness levels through heat treatment like quenching and tempering. It simply responds more strongly to hardening processes.
The alloying elements work together effectively. Chromium (Cr, usually 0.80-1.10%) and Molybdenum (Mo, usually 0.15-0.25%) significantly boost the steel's hardenability – its capacity to harden deeply when quenched. This means even thicker sections can achieve high hardness throughout. These elements also contribute to overall strength, toughness, and resistance to wear. Manganese (Mn, typically 0.75-1.00%) further helps with hardenability and strength.
What you get is a steel known for an excellent package: high tensile strength, good toughness (especially when properly tempered after hardening), impressive resistance to fatigue failure, and very good resistance to abrasion and impact, particularly once it's hardened. Now, the higher carbon does make welding a bit more demanding than with 4130. Careful pre-heating and post-heating procedures are often necessary to prevent cracking, but it's definitely weldable with the right expertise. AISI 4140 is widely chosen for parts needing high strength, resistance to wear, and durability under heavy stress. When supplied as ASTM A519 Grade 4140 seamless tubing or pipe, it provides outstanding structural integrity for tough mechanical and certain pressure applications.
AISI 4140 Specifications: The Technical Details
Ensuring the material meets the correct technical standards is critical for performance and safety, especially in high-strength uses. USA Piping Solution supplies AISI 4140 Tubes & Pipes manufactured and tested according to the key industry specifications, primarily ASTM A519 for seamless mechanical products.
Core Technical Specifications
| Specification | Details |
|---|---|
| Primary Standard | ASTM A519 / ASME SA519 - covers Seamless Carbon and Alloy Steel Mechanical Tubing. Grade 4140 falls under this standard. Even when ordered in pipe dimensions (NPS/Schedule), ASTM A519 governs seamless 4140 mechanical products. |
| How It's Made |
Primarily supplied as Seamless for superior structural integrity. Welded options exist under
different specs but are rare for 4140. Available finishes include:
|
| Material Condition |
Offered in several material conditions based on end-use requirements:
|
| Size Range (OD & WT) | Available from small mechanical tube sizes up to large pipes (12" NPS or larger). Wall thickness options range from medium to very heavy-duty, suitable for high-stress applications or machining stock. |
| Lengths | Supplied in standard random lengths (Single Random Lengths [SRL] / Double Random Lengths [DRL]) or cut to specified customer requirements. |
Meeting the ASTM A519 spec ensures the 4140 Mechanical Tubing fulfills requirements for dimensions, manufacturing process, and basic testing. Specific Q&T properties need to be agreed upon.
Material Makeup and Strength Capabilities
The impressive strength and toughness potential of AISI 4140 Tubes & Pipes come directly from its specific chemical blend and how effectively it responds to heat treatment.
Chemical Composition (Typical Weight %)
| Element | Content (%) | What It Does for 4140 |
|---|---|---|
| Carbon (C) | 0.38 - 0.43 | Higher carbon enables high hardness/strength via heat treat |
| Manganese (Mn) | 0.75 - 1.00 | Boosts hardenability and contributes to strength |
| Chromium (Cr) | 0.80 - 1.10 | Crucial for hardenability and adds wear resistance |
| Molybdenum (Mo) | 0.15 - 0.25 | Improves hardenability, toughness, and hot strength |
| Silicon (Si) | 0.15 - 0.35 | Primarily removes oxygen during steelmaking |
| Phosphorus (P) | ≤ 0.035 | Impurity, level is controlled for toughness |
| Sulfur (S) | ≤ 0.040 | Impurity, controlled (can slightly help machinability) |
Mechanical Property Ranges
Keep in mind, the actual properties of 4140 vary greatly depending on how it's heat treated. Here are typical minimums often seen for common states:
| Property | Annealed (Approx.) | Q&T (Common Target*) | Significance |
|---|---|---|---|
| Tensile Strength | ~655 MPa (95 ksi) | 850-1000+ MPa (125-150+ ksi) | Ultimate pulling strength before breaking |
| Yield Strength | ~415 MPa (60 ksi) | 690-850+ MPa (100-125+ ksi) | Stress needed to cause permanent deformation |
| Elongation (in 2") | ~20%+ | 15-20%+ | How much it stretches (ductility, lower when harder) |
| Hardness | ~197 HB / ~95 HRB | 28-38+ HRC | Resistance to denting (highly variable) |
*Q&T properties are adjustable. Engineers specify targets based on tempering temperature to get the desired strength/toughness balance.
Achieving high strength requires proper Quenching and Tempering. USA Piping Solution can supply 4140 heat-treated to meet specific strength, hardness, or industry standards (like certain API requirements).
Common Types & Forms of AISI 4140
USA Piping Solution offers versatile AISI 4140 Tubes & Pipes in several useful configurations:
- Round Tubes / Pipes: This is the most common form factor. You can get 4140 Seamless Pipe (often made to A519 specs but sized like pipe) and 4140 Mechanical Tubing (ordered by OD/Wall). They're widely used for shafts, axles, structural parts, and some pressure-rated applications.
- Square / Rectangular Tubes: While less common in seamless 4140 than round, these shapes might be sourced for specific high-strength structural applications where flat sides are beneficial.
- Production & Finish:
- Seamless: The standard for A519 Grade 4140, offering the best structural uniformity.
- Hot-finished (HF): The basic condition after hot forming.
- Cold Drawn (CD): Provides tighter tolerances and smoother finishes, sometimes preferred for precision parts.
- Heat Treatment States:
- Annealed: Supplied in the softest condition, best if you plan extensive machining or forming.
- Normalized: Offers a uniform structure, often a good starting point with better machinability than as-rolled.
- Quenched & Tempered (Q&T): Specifically heat-treated to reach high hardness and strength levels needed for tough jobs.
This variety allows you to choose the best starting material based on your fabrication process and the final part's required properties.
Where is AISI 4140 Used? Key Industries
The high strength, toughness, and wear resistance combination makes AISI 4140 Tubes & Pipes a workhorse in demanding sectors:
- Oil & Gas: Durable for downhole tools, tool joints, high-pressure components, manifolds, and valve parts—often Q&T to API specs.
- Automotive: Used in axles, crankshafts, connecting rods, gears, and steering parts where fatigue resistance is critical.
- Aerospace: Landing gear parts, actuator shafts, structural fittings requiring high reliability and strength.
- Heavy Machinery & Equipment: Shafts, gears, axles, spindles, couplings, and construction or mining machinery parts.
- Power Generation: High-strength fasteners, shafts, turbine components needing stress durability.
- Hydraulics: High-pressure cylinders, piston rods, and fittings requiring excellent strength and toughness.
- Tooling and Manufacturing: Dies, molds, chucks, fixtures where high hardness and toughness are required.
Basically, ASTM A519 Grade 4140 is chosen when higher strength and wear resistance are critical compared to lower carbon steels like 4130 or mild steels.
Guide to AISI 4140 Sizes
USA Piping Solution carries a wide selection of AISI 4140 Tubes & Pipes, focusing on dimensions frequently used in mechanical and oilfield work:
- ODs: From around 2" OD tubing up to 12" NPS pipe sizes and sometimes larger.
- Wall Thicknesses: Emphasis on medium to very heavy walls suitable for high-stress jobs or providing machining stock (e.g., pipe schedules 120, 160, XXH, heavy wall tubing up to 1.5"+).
(Note to Design Team: Insert a concise size chart table with common OD x Wall or NPS x Schedule examples for AISI 4140, highlighting availability of heavy walls.)
| Type | Example Size | Example Schedule / Wall | Typical Condition |
|---|---|---|---|
| Pipe (A519) | 4" NPS | XXH (0.674" Wall) | Q&T |
| Tube (A519) | 7" OD | 1.250" Wall | Normalized |
| ...(add 1-2 more) |
Inventory changes. Contact
Certifications & Compliance You Can Trust
Ensuring material integrity is absolutely critical for high-strength alloys like 4140 Alloy Steel Tubing. USA Piping Solution provides complete certification:
- Standard Compliance: Certified conformance to ASTM A519 / ASME SA519 Grade 4140.
- Heat Treatment Verification: MTRs confirm heat treatment and mechanical properties (strength, hardness) when supplied Q&T or Normalized.
- Industry Specs: Can be supplied meeting API strength levels or NACE MR0175 / ISO 15156 requirements.
- Quality System: ISO 9001:2015 managed operations.
- MTRs: Provided per EN 10204 3.1 or equivalent, documenting full material traceability.
- TPI: Third-party inspection services available upon request.
Why USA Piping Solutions for AISI 4140?
Sourcing AISI 4140 Tubes & Pipes from USA Piping Solutions provides reliable access and valuable support:
- Strong 4140 Inventory: Large US stock, especially heavy walls and heat-treated material.
- Heat Treat Options: Annealed, Normalized, or Q&T as needed.
- Custom Processing: Precision cutting to specified lengths.
- Global Shipping Handled: Efficient worldwide logistics support.
- Industry Experience: Oil & gas, automotive, aerospace, and machinery expertise.
- Technical Assistance: Guidance on specifications and applications.
- Competitive Value: High-quality 4140 material at competitive pricing.
We are your trusted AISI 4140 Pipe Supplier.
Exploring Related Alloy Steel Products
While AISI 4140 offers high strength, USA Piping Solutions also provides other relevant grades:
Ready to Get Your High-Strength AISI 4140?
Need high-performance AISI 4140 Tubes & Pipes for tough engineering jobs? When your project demands exceptional strength, toughness, and wear resistance, USA Piping Solutions has the materials you need.
We supply top-quality 4140 Alloy Steel Tubing and pipes, mostly seamless, meeting global standards like ASTM A519 Grade 4140. Perfect for heavy-duty industries like oil & gas, automotive, and aerospace, our products come in various sizes and heat-treated conditions. You get:
✅ Competitive pricing
✅ Custom sizes & heat treatment options
✅ Fast global shipping with full MTCs
Contact us now! Request a quote or consult our alloy steel specialists about your specific AISI 4140 Pipe Supplier needs.
Request Your AISI 4140 Pipe Quote Today!
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