EN 10305-1 Grade E235 Carbon Steel Tubes Manufacturer & Supplier - USA Piping Solution

USA Piping Solution is a premier national supplier of EN 10305-1 Grade E235 Carbon Steel Tubes. This European standard specifies the technical delivery conditions for seamless cold-drawn steel tubes intended for precision applications. Grade E235 represents a commonly utilized low-carbon steel offering excellent formability and weldability. We maintain significant inventories across the United States, ensuring reliable access to certified EN 10305-1 Grade E235 Carbon Steel Tubes for demanding mechanical and engineering requirements. Partner with USA Piping Solution for quality materials, technical expertise, and efficient nationwide distribution.

What is EN 10305-1 Grade E235 Carbon Steel Tube?

The designation EN 10305-1 Grade E235 Carbon Steel Tube refers to seamless precision steel tubing manufactured according to the European standard EN 10305-1. This standard specifically addresses seamless cold-drawn tubes used in applications demanding high dimensional accuracy, smooth surfaces, and defined mechanical properties. The "E235" grade identifier signifies a non-alloy quality steel with a specified minimum yield strength of 235 MPa in the normalized condition.

Key characteristics defined by this standard and grade include:

• European Standard (EN): Conformance to EN 10305-1 ensures compliance with specific European technical delivery conditions, distinct from ASTM or DIN standards, although functional equivalents often exist (E235 is broadly similar to DIN 2391 St37 or some grades within ASTM A519).
• Seamless Construction: Production begins with seamless hollows, ensuring the final tube lacks a longitudinal weld seam, contributing to uniform structure and integrity.
• Cold Drawn Finish: The defining manufacturing step involves cold drawing the seamless hollow through dies (and potentially over mandrels). This process imparts the "precision" characteristics: tight dimensional tolerances, excellent surface finish (both OD and ID), and increased strength/hardness compared to hot-finished products (though properties depend on final heat treatment).
• E235 Grade Steel: This designates a low-carbon steel (Carbon ≤ 0.17%) known for its good ductility, excellent weldability, and suitability for various forming operations, especially when supplied in an annealed or normalized state.

Engineers and manufacturers specify EN 10305-1 Tubes in Grade E235 when applications require the reliability of seamless construction combined with the superior dimensional control and surface quality provided by cold drawing, utilizing a versatile and formable low-carbon steel. These Seamless Precision Tubes are essential for many high-performance mechanical and fluid power systems.

EN 10305-1 E235 Tube Specifications

Precise adherence to the technical parameters outlined in EN 10305-1 is fundamental for ensuring the proper function and reliability of E235 tubes in precision applications. USA Piping Solution supplies materials verified against these specific criteria.

Technical Specifications

Property	Description
Governing Standard:	EN 10305-1 (Seamless cold drawn tubes for precision applications - Technical delivery conditions).
Grade Designation:	E235 (indicating minimum yield strength of 235 N/mm² in the normalized condition). Material number often 1.0308.
Manufacturing Process:	Seamless production followed by Cold Drawing.
Delivery Conditions:	The final properties depend heavily on the delivery condition specified using standard suffixes: +C: Cold Drawn / Hard (As-drawn, highest strength, low ductility). +LC: Cold Drawn / Soft (Lightly cold worked after last heat treatment, improved ductility vs. +C). +SR: Cold Drawn / Stress Relieved (Stresses from cold drawing reduced). +A: Annealed (Fully softened after cold drawing for maximum ductility). +N: Normalized (Heat treated after cold drawing for refined grain structure, balanced properties - this is the condition where the 235 MPa yield strength is defined).
Size Range (Outside Diameter - OD):	The standard covers a wide range, but typical precision applications often utilize ODs from a few millimeters up to around 100 mm or more.
Wall Thickness:	Available in various wall thicknesses, often specified precisely in millimeters.
Length Options:	Supplied in standard manufacturing lengths (e.g., 4-7 meters) or cut to specific lengths required for component production.
Dimensional Tolerances (Refer to EN 10305-1):	A primary feature is the tight dimensional control. Tolerances on OD, ID (if applicable), and wall thickness are significantly stricter than standard pipe or hot-finished tube specifications. Straightness tolerances are also defined.

Chemical Composition and Mechanical Properties

The performance characteristics of EN 10305-1 Grade E235 Carbon Steel Tubes, such as formability, strength, and weldability, are directly governed by its low-carbon chemistry and the mechanical properties achieved through cold drawing and subsequent heat treatment (delivery condition).

Chemical Composition of EN 10305-1 E235 Tubes (% by Weight)

Grade E235 specifies a non-alloy quality steel composition suitable for general precision applications.

Element	E235 Requirement (%)	Significance for Performance
Carbon (C)	≤ 0.17	Low carbon ensures excellent ductility, formability, and weldability.
Silicon (Si)	≤ 0.35	Deoxidizing element present from steelmaking.
Manganese (Mn)	≤ 1.20	Contributes to strength and deoxidation.
Phosphorus (P)	≤ 0.025	Impurity level restricted for material quality and toughness.
Sulfur (S)	≤ 0.025	Impurity level limited for improved ductility and surface characteristics.
Aluminum (Al)	≥ 0.015 (Optional)*	May be added for grain refinement, especially if specified fully killed.

Note: This represents the ladle analysis. Slight variations are permitted in product analysis per the standard. Aluminum content relates to deoxidation practice.

Mechanical Properties of EN 10305-1 E235 Tubes (Condition Dependent)

The mechanical properties vary significantly based on the final delivery condition after cold drawing. EN 10305-1 provides minimum values for each condition:

Property	+C (Hard)	+LC (Soft)	+SR (Stress Relieved)	+A (Annealed)	+N (Normalized)	Units	Interpretation
Tensile Str. (Rm)	≥ 480	≥ 420	≥ 420	≥ 315	340 - 480	MPa	Highest in +C; lowest in +A; +N provides a defined range.
Yield Str. (ReH)	(~350+)	(~315+)	≥ 350	(~190+)	≥ 235	MPa	Defined minimum only for +SR and +N. Significantly higher in +C, lower in +A.
Elongation (A5)	≥ 6%	≥ 10%	≥ 16%	≥ 25%	≥ 25%	%	Ductility is lowest in +C, highest in +A and +N conditions.

Key Points on Conditions:

• +C (Cold Drawn/Hard): Offers maximum strength from cold work but very limited ductility. Suitable when strength is the main factor and little forming is needed.
• +LC (Cold Drawn/Soft): Slightly more ductile than +C due to lighter final processing or heat treatment.
• +SR (Stress Relieved): Reduces internal stresses from cold work, improving stability, while largely maintaining the high strength of the +C condition. Minimum yield strength is specified.
• +A (Annealed): Provides maximum softness and ductility, ideal for severe bending, flaring, or forming operations. Has the lowest strength.
• +N (Normalized): Offers a good balance of moderate strength (with a defined minimum yield of 235 MPa), excellent ductility (comparable to annealed), and a refined, uniform grain structure. A very common and versatile condition.

Selecting the correct delivery condition (+C, +LC, +SR, +A, +N) is crucial for matching the tube's properties to the fabrication requirements and service demands of the application.

Types and Delivery Conditions of EN 10305-1 E235 Tubes

EN 10305-1 focuses specifically on seamless cold drawn tubes. While the manufacturing method is fixed (seamless followed by cold drawing), the critical variation lies in the delivery condition, which dictates the final mechanical properties and suitability for different fabrication processes.

As detailed previously, the common delivery conditions defined in EN 10305-1 for E235 tubes are:

• +C (Cold Drawn / Hard): Delivered in the as-drawn state after the final cold working pass. This condition maximizes the strength increase due to work hardening but results in low ductility. Suitable for applications prioritizing strength where minimal forming is required, or where subsequent machining will be the primary operation. Symbol: BK in older DIN standards.
• +LC (Cold Drawn / Soft): Receives a final heat treatment after cold drawing that results in only slight cold work effect remaining. Offers improved ductility compared to +C, making it suitable for moderate forming. Symbol: BKW in older DIN standards.
• +SR (Cold Drawn / Stress Relieved): Undergoes a stress relieving heat treatment after the final cold drawing pass. This reduces internal stresses (improving dimensional stability during machining) while largely maintaining the high hardness and strength achieved through cold working. Symbol: BKS in older DIN standards.
• +A (Annealed): Fully annealed in a controlled atmosphere furnace after the final cold drawing pass. This produces the softest condition with maximum ductility, ideal for applications requiring severe bending, flaring, or complex forming. Symbol: GBK in older DIN standards.
• +N (Normalized): Heat treated by normalizing after the final cold drawing pass. This refines the grain structure, providing a good balance of strength (significantly higher than annealed), excellent ductility (comparable to annealed), toughness, and often improved machinability compared to the +C condition. Symbol: NBK in older DIN standards. This is a very common and versatile delivery condition for E235 precision tubes.

The choice of delivery condition is a primary specification requirement and must be based on the intended fabrication methods (machining, bending, flaring) and the final mechanical properties needed for the application. USA Piping Solution can assist in sourcing tubes in the required delivery condition based on availability.

Applications and Industries Served

The precision, smooth finish, and reliable properties of EN 10305-1 Grade E235 Carbon Steel Tubes make them suitable for a diverse range of applications, particularly where dimensional accuracy is key:

• Hydraulic & Pneumatic Systems: Extensively used for fluid power lines, especially in the +N (Normalized) condition due to its excellent balance of formability (for bending/flaring) and strength. Also used for components like cylinder barrels (often requiring honing) and piston rods.
• Automotive Components: Employed in manufacturing various parts requiring precision, such as fuel injection lines, steering system components, suspension parts, axles, camshafts, and structural elements within the chassis.
• Machinery & Equipment Manufacturing: Serves as stock material for producing precision shafts, axles, rollers, bushings, guide rods, machine frames, and numerous other components demanding tight tolerances and good surface quality.
• General Engineering & Fabrication: Used widely for producing custom-machined parts, tooling, fixtures, spacers, connectors, and other engineered components where dimensional accuracy reduces subsequent processing.
• Furniture Production: Utilized in high-quality metal furniture designs requiring smooth surfaces and consistent dimensions for frames and structural elements.
• Instrumentation Tubing: Suitable for certain instrumentation and control system applications where precision seamless tubing is necessary.

E235 Cold Drawn Tubes are chosen when standard pipe or hot finished tubing lacks the required dimensional precision or surface finish for the final component or assembly. The selection of the appropriate delivery condition (+C, +A, +N, etc.) further tailors the tube to the specific fabrication and performance needs.

EN 10305-1 E235 Tube Size Chart and Tolerances

Precision is the defining feature of EN 10305-1 Tubes. This standard specifies significantly tighter dimensional tolerances compared to general-purpose pipe or tubing standards.

Typical Size Range:

• Outside Diameter (OD): Commonly available from ~4 mm up to ~100 mm+, depending on manufacturer.
• Wall Thickness: Ranges from very thin (~0.5 mm) up to substantial walls (~10 mm+), relative to the OD.

Dimensional Tolerances (Illustrative Examples from EN 10305-1):
Tolerances are a key reason for specifying this standard. They are significantly tighter than standard pipe. Note: The standard contains detailed tables; these are simplified examples.

• Outside Diameter (OD) Tolerance:
• For OD ≤ 40 mm: Often within ±0.08 mm to ±0.15 mm (depending on exact OD/Wall and condition).
• For 40 mm < OD ≤ 80 mm: Often within ±0.20 mm to ±0.30 mm.
• For 80 mm < OD ≤ 120 mm: Often within ±0.30 mm to ±0.40 mm.
• Wall Thickness Tolerance: Typically ±10% of the nominal wall thickness (or tighter options may be available by agreement).
• Inside Diameter (ID) Tolerance: Can be controlled if specified, particularly when drawn over a mandrel. Tolerances are similar in magnitude to OD tolerances.
• Straightness: Typically specified as deviation over a 1-meter length (e.g., 1 mm/m or 0.5 mm/m for special straightness).

Weight Chart (Calculated Examples):
Weights are based on nominal dimensions and a steel density of approximately 7.85 g/cm³.

OD (mm)	Wall (mm)	ID (mm)	Weight ( kg/m )	Weight (lbs/ft)
10.0	1.0	8.0	0.23	0.15
16.0	1.5	13.0	0.55	0.37
20.0	2.0	16.0	0.90	0.61
25.0	2.5	20.0	1.41	0.95
30.0	3.0	24.0	2.01	1.35
38.0	4.0	30.0	3.44	2.31
45.0	3.0	39.0	3.11	2.09
50.0	5.0	40.0	5.71	3.84
60.0	6.0	48.0	8.06	5.42
76.1	5.0	66.1	8.90	5.99
88.9	6.0	76.9	12.3	8.28
101.6	7.0	87.6	16.3	11.0

Disclaimer: This is illustrative. Actual tolerances are detailed in EN 10305-1 and affect weight. Consult the standard for precise values.

Certifications and Compliance

Ensuring EN 10305-1 Grade E235 Carbon Steel Tubes meet the standard's requirements is confirmed through appropriate certifications and quality control measures.

• EN 10305-1 Compliance: Materials supplied are certified by the manufacturer to conform fully to the technical delivery conditions specified in EN 10305-1 for Grade E235. This covers chemical composition, the seamless cold-drawn manufacturing process, dimensional tolerances, surface quality, and the mechanical properties corresponding to the ordered delivery condition (+C, +A, +N, etc.).
• Mill Certification (EN 10204): Typically provided with inspection documents according to EN 10204, commonly Type 3.1. This certificate provides traceability via heat/lot numbers and confirms the results of ladle chemical analysis and mandatory mechanical tests relevant to the specified delivery condition.
• ISO 9001 Quality Management: Our operations are guided by ISO 9001 certified quality systems, ensuring consistent practices in supplier vetting, material verification, and order fulfillment.
• Standard Markings: Tubes are marked according to EN 10305-1 and standard practice (method varies by size), usually including:
• Manufacturer's mark
• Standard reference (EN 10305-1)
• Grade (E235) and Delivery Condition (e.g., +N)
• Dimensions (OD x Wall)
• Heat number or traceability code.

This documentation provides the necessary assurance of material conformity for precision engineering applications.

Why Choose USA Piping Solution for EN 10305-1 E235 Tubes?

Sourcing European standard precision tubing requires a supplier with specific capabilities and access. USA Piping Solution offers distinct advantages for procuring EN 10305-1 E235 Tubes:

• Expertise in Precision Standards: Our team understands the nuances of EN 10305-1, including the significance of grade E235 and the critical impact of delivery conditions (+C, +A, +N) on performance.
• Global Sourcing Network: We maintain strong relationships with qualified international mills specializing in the production of high-quality seamless precision tubes meeting EN standards.
• Efficient Import & Logistics: We manage the complexities of importing and distributing these materials, providing reliable access and timely delivery across the United States from our domestic stock points.
• Commitment to Quality: We prioritize sourcing from reputable manufacturers and ensure comprehensive mill certification (EN 10204 3.1) accompanies materials to verify full compliance.
• Value-Added Processing: We offer precision cutting-to-length services, enabling delivery of tubes ready for immediate integration into your manufacturing processes.
• Responsive Technical Support: Our knowledgeable staff provides prompt assistance with inquiries, offers accurate technical information, and ensures efficient order management.

Related Products

USA Piping Solution supplies a wide array of tubular products meeting various international and domestic standards:

Selecting the correct standard and grade depends entirely on the specific requirements of your application regarding precision, strength, formability, temperature, and pressure. Our team can assist in navigating these choices.

Final Call to Action

For precision applications demanding the tight tolerances, smooth finish, and reliable properties of EN 10305-1 Grade E235 Carbon Steel Tubes, rely on USA Piping Solution. We provide access to certified E235 Cold Drawn Tubes and Seamless Precision Tubes meeting this European standard, supported by our efficient sourcing and distribution network. Ensure the quality and accuracy of your components with materials from a dependable supplier.

Contact USA Piping Solution today to discuss your EN 10305-1 Grade E235 Carbon Steel Tubes requirements and receive a detailed, competitive quotation.

Request Your EN 10305-1 E235 Tube Quote Now!