ST37 Welded Tubes Manufacturer & Supplier – USA Piping Solution

Finding the right steel tubing often involves balancing performance, workability, and cost. For a huge range of structural and mechanical tasks, St37 Welded Tubes consistently hit that mark, offering a blend of reliability and ease of use recognized across industries. USA Piping Solution stands as a key manufacturer and trusted supplier of this essential Welded Carbon Steel Tube, primarily produced using robust ERW techniques according to established DIN and equivalent standards. We know that engineers rely on the dependable nature of St37 Steel Tubes for everything from automotive frames to industrial machinery. That’s why we offer not just stock material, but tailored solutions, including various dimensions and custom lengths, all backed by the quality assurance and global service capabilities of USA Piping Solution.

Getting to Know St37 Steel

St37 isn't just a technical code; it represents a widely trusted grade of low-carbon, unalloyed mild steel, historically rooted in German DIN standards (like DIN 17100 or tube-specific standards DIN 1626/2394). While modern European standards (like EN 10025 S235JR) often serve as its successor, the St37 designation remains familiar and frequently specified. What has made this particular steel grade so enduringly popular? It comes down to a combination of highly practical advantages:

• Superb Weldability: This is perhaps its most celebrated trait. Thanks to the low carbon content, joining St37 using common fusion welding methods is typically straightforward. The need for pre-heating or complex post-weld treatments is often eliminated, which translates directly into faster, more cost-effective fabrication.
• Good Machinability: It behaves predictably under cutting tools. St37 can be drilled, milled, turned, and shaped efficiently using standard workshop practices, making component production less complex.
• Reliable Strength: While not a high-strength alloy, St37 provides a solid foundation of tensile and yield strength perfectly adequate for countless structural supports, machine frames, and general mechanical parts.
• Forming Potential: It possesses good ductility, meaning it can be bent, pressed, or drawn into various configurations without excessive risk of fracture, offering valuable design flexibility.
• Economic Value: As a standard, non-alloyed mild steel, St37 typically presents an attractive cost profile compared to steels offering higher strength or specialized corrosion resistance.

In essence, St37 Carbon Steel Tubes are the quintessential "go-to" material for a multitude of everyday engineering challenges. They are the reliable workhorse – easy to source, easy to work with, and strong enough for the job, making these Mild Steel Tubes or Low Carbon Steel Tubes indispensable.

St37 Welded Tube Specifications Unpacked

To ensure the St37 tubing you source aligns perfectly with your design intent and quality expectations, understanding the key specifications is vital. USA Piping Solution delivers St37 Welded Tubes manufactured under controlled processes that meet relevant standards.

Technical Specifications

Specification Aspect	Typical Details & Considerations
Grade Reference	St37 (often linked to DIN standards like DIN 2394, DIN 1626, or DIN 17100). Often considered equivalent to EN 10025 S235JR in properties.
Relevant Standards	DIN 2394 (Welded Precision), DIN 1626 (General Welded), EN 10219 (Structural Hollow Sections), EN 10305-3/5 (Welded Precision/Structural).
Primary Production	Electric Resistance Welding (ERW) / High-Frequency Induction (HFI) is the standard for this grade. Cold Drawn Welded (CDW) offers tighter tolerances.
Outer Diameter (OD)	A very broad range is typically produced, from small diameters around 6mm up towards 355mm or even larger structural sections.
Wall Thickness (WT)	Spans from relatively thin gauges (e.g., 0.5mm - 1mm) up to more robust walls (e.g., 10mm, 12mm, sometimes thicker depending on OD/standard).
Lengths Provided	Standard 6-meter lengths are common, but custom cutting to specific project lengths is a standard service offering.
Common Shapes	While Round Tubes are fundamental, Square and Rectangular hollow sections made from St37 steel are extremely common, often specified under EN 10219.
Typical Surface	Usually supplied as-welded (often 'black' or with mill scale), though pickled & oiled or cold-finished conditions are possible depending on the exact standard.
End Type	Predominantly Plain Ends (PE).

Given the evolution of standards (DIN to EN), it's always wise to confirm the precise standard being applied to your order (e.g., DIN 2394 vs. EN 10305-3) to ensure alignment on tolerances and testing.

The Chemical Recipe of St37

The reliable performance of St37 steel, particularly its notable weldability, is directly linked to its straightforward, low-carbon chemical composition. Adhering to base material standards like DIN 17100 or EN 10025 S235JR, the typical limits are:

Element	Symbol	Typical Max % by Weight	Impact on Material Behavior
Carbon	C	≤ 0.17% (often below 0.15%)	This low carbon level is the defining factor for its excellent weldability and good ductility.
Manganese	Mn	≤ 1.40%	Contributes significantly to achieving the required strength levels without unduly harming weldability.
Phosphorus	P	≤ 0.045% (often tighter limits)	Kept low, as excess phosphorus can make the steel less tough.
Sulfur	S	≤ 0.045% (often tighter limits)	Also controlled tightly; lower sulfur improves weld quality and overall material toughness.
Nitrogen	N	Often controlled (e.g., ≤ 0.009%)	Nitrogen levels can influence toughness, particularly after certain processing steps.
Iron	Fe	Balance	The fundamental element comprising the vast majority of the steel.

This uncomplicated yet effective chemistry makes St37 Carbon Steel Tubes both economical to produce and remarkably easy for fabricators to work with.

Understanding St37's Mechanical Strength

St37 steel provides a dependable level of mechanical performance well-suited to its common applications. These properties ensure it can handle typical structural loads and mechanical stresses effectively. Based often on the source material standard (like EN 10025 S235JR), here are the minimum mechanical values engineers typically work with:

Property	Common Minimum Value / Range	What it Means Practically
Tensile Strength (UTS)	340 – 470 MPa (Approx. 49 - 68 ksi)	The maximum pulling force the steel can take before it starts to significantly weaken and break.
Yield Strength (ReH)	≥ 235 MPa (Approx. ≥ 34 ksi)	The critical point where the material begins to deform permanently under load. This is key for structural safety calculations.
Elongation (A%)	≥ 25% (Can be higher for thin material)	A good indicator of ductility, showing it can stretch quite a bit before fracturing, which is beneficial for bending and forming.
Hardness (Brinell)	Typically ≤ 150 HB (in annealed state)	Reflects its relative softness, contributing to its good machinability and formability.

These figures confirm St37 provides a reliable foundation for general-purpose engineering. Keep in mind that processes like cold drawing (Cold Drawn Welded Tubes) naturally increase the yield and tensile strength figures, usually with a corresponding reduction in the elongation percentage.

Available Forms and Types

To meet the varied needs of different industries and fabrication methods, USA Piping Solution primarily offers St37 steel tubing in welded configurations, leveraging the efficiency of this process for this grade:

1. St37 ERW Welded Tubes:
• This is the most prevalent form, produced via Electric Resistance Welding. It offers a reliable and cost-effective tubing solution suitable for a vast array of structural and mechanical tasks, available in round, square, and rectangular profiles.
2. St37 Seamless Tubes:
• While welded is more common for St37, seamless tubes made from this grade (often specified under DIN 2391 St37 or the equivalent EN 10305-1 E235) are also produced. Seamless construction eliminates the weld zone entirely, sometimes preferred for specific pressure applications or where absolute uniformity is paramount. USA Piping Solution can readily source seamless St37 when required.
3. Cold Drawn Welded (CDW) Tubes:
• These tubes begin as standard ERW but undergo a secondary cold drawing process. This refines the dimensions, improves the surface finish, and increases the mechanical strength properties compared to the original ERW tube.
4. Hot Rolled Welded Tubes:
• Generally produced directly from hot-rolled steel, resulting in wider dimensional tolerances and a characteristic mill scale surface. Often suitable for less critical structural applications where precision is secondary.
5. Profile Variations:
• Beyond the standard Round Tubes, St37 is extensively used to produce Square Tubes and Rectangular Tubes, which are fundamental building blocks in countless structural designs and frameworks.

Where St37 Welded Tubes Find Their Place

The practical nature and economic viability of St37 Welded Tubes make them a ubiquitous material across many sectors:

• Construction & Structural Frameworks: Foundational for building frames, roof support systems, scaffolding components, safety railings, support columns, and general steel construction needs.
• Automotive Applications: Used for vehicle chassis elements, seat frames, cross-members, and other structural parts where moderate strength and excellent weldability are key requirements. (Note: High-stress safety components may use higher grades).
• Machine Building & Equipment: Forms the sturdy frames and bases for machinery, conveyor system structures, support legs, and various non-critical mechanical parts.
• General Engineering & Fabrication: A highly popular choice for countless fabricated items, including support brackets, workbenches, mounting structures, agricultural equipment components, and workshop fixtures.
• Furniture Design & Manufacturing: Provides the strong, yet formable, framework for durable industrial, commercial, and even domestic furniture pieces.
• Fencing, Gates & Enclosures: Commonly forms the posts, rails, and frames for fencing systems, gates, and various types of protective enclosures.

Its straightforward fabrication characteristics make St37 a favorite among welding shops and fabricators

Navigating the Size Range

USA Piping Solution offers St37 Welded Tubes across a truly extensive range of sizes. The table below provides just a glimpse into typical Outside Diameter (OD) and Wall Thickness (WT) combinations for round tubes. Keep in mind that square and rectangular sections also cover a vast dimensional matrix.

Outer Diameter (OD)	Frequently Stocked Wall Thicknesses (WT)
mm	mm
15 - 25 mm	1.0, 1.2, 1.5, 2.0
26 - 40 mm	1.2, 1.5, 2.0, 2.5, 3.0
41 - 60 mm	1.5, 2.0, 2.5, 3.0, 3.5, 4.0
61 - 80 mm	2.0, 2.5, 3.0, 3.5, 4.0, 5.0
81 - 120 mm	2.5, 3.0, 3.5, 4.0, 5.0, 6.0
121 - 160 mm	3.0, 3.5, 4.0, 5.0, 6.0, 8.0
161 - 220 mm	4.0, 5.0, 6.0, 8.0, 10.0
221 - 355 mm	5.0, 6.0, 8.0, 10.0, 12.0, and often thicker options available for structural profiles.

This is purely representative. Our actual inventory is significantly larger and includes many intermediate sizes and common imperial equivalents. Please contact USA Piping Solution with your specific dimensional needs for accurate stock information.

Our Commitment to Certifications & Compliance

Ensuring your materials meet the required standards is fundamental. USA Piping Solution provides St37 Welded Tubes backed by robust quality management and clear documentation:

• DIN / EN Standard Adherence: We supply materials verified against the relevant DIN standards (like DIN 2394) or their modern EN equivalents (such as EN 10305-3/5, EN 10219), ensuring they meet the specified chemical, mechanical, and dimensional criteria.
• ISO 9001:2015 Certified Operations: Our quality management system holds ISO 9001 certification, signifying a commitment to consistent processes, product quality, and continual improvement.
• Certified Mill Test Reports (MTCs): Standard procedure involves providing MTCs conforming to EN 10204 3.1. These documents guarantee full traceability through heat or lot numbers and provide verified chemical analysis and mechanical test results for the specific batch supplied.
• EN 10204 3.2 Available: Should your project demand certification witnessed and validated by an authorized third-party inspector, we can arrange for EN 10204 3.2 compliance upon request.
• Third-Party Inspection (TPI) Support: We routinely facilitate inspections by customer-appointed or independent third-party agencies to provide additional verification and meet specific contractual requirements.

Why Choose USA Piping Solutions?

When you select USA Piping Solution for your St37 Welded Tubes, you gain more than just material; you gain a reliable partner offering distinct advantages:

• Ready Inventory & Sourcing Power: Our significant stock levels in common St37 sizes (round, square, rectangular) often mean quicker deliveries. We also have the capability to source St37 Seamless Tubes when your application demands it.
• Tailored to Your Process: We offer precision cut-to-length services, minimizing your preparation time and material waste. Discuss any other specific processing needs with our team.
• Global Reach, Local Understanding: We manage logistics effectively, delivering reliably across the US and handling export compliance for international shipments.
• Assured Quality, Competitive Value: Our focus on standards (DIN/EN, ISO 9001) and comprehensive MTCs ensures quality, while our efficient operations allow for competitive pricing.
• Seamless Inspection Coordination: If TPI is required, we handle the coordination smoothly, integrating it into the delivery timeline.
• Responsive & Knowledgeable Team: Our staff understands steel tubing specifications and applications, ready to provide clear answers and helpful guidance.

Related Products

Our extensive inventory includes other relevant carbon steel and related tubular products:

Final Call to Action

Searching for dependable St37 Welded Tubes to form the foundation of your next structural or industrial project? USA Piping Solution is your definitive source. We supply high-quality St37 Steel Tubes, manufactured to meet global standards and deliver the excellent weldability, formability, and reliable strength that engineers count on. From extensive stock to custom orders, trust us for superior materials and responsive service.

Request Your St37 Welded Tubes Quote Today!