EN 10305-3 / 28Mn6 Welded Cold-Sized Carbon Steel Tube for Precision Applications

Material Overview

EN 10305-3 (Welded Cold-Sized Tubes) defines the technical delivery conditions for welding cold-sized steel tubes used in precision applications.
“28Mn6” (steel number 1.1170) is a heat-treatable, manganese-containing carbon steel grade commonly used in mechanical and automotive applications.

When used in welded cold-sized tubes under EN 10305-3, 28Mn6 provides a balance of strength, formability, and weldability, making it suited for structural and precision uses.

Specifications

Below is a representative (“typical”) specification summary (not a full standard text):

• Product Type: Welded cold-sized (i.e. welded and then cold reduced for precise tolerance) steel tubes (circular, square, rectangular cross-sections)

• Maximum Outside Diameter (circular): up to 193.7 mm according to the standard scope

• Tolerance & Surface Roughness: tight dimensional tolerances and a maximum permitted surface roughness (not freely given in summary sources)

• Heat-treatment / Delivery Conditions: as-welded, cold-sized, optionally normalizing, annealing, or quench & tempering depending on requirements and grade

• Typical Wall Thickness / Lengths: common ranges (e.g. wall thickness from ~0.5 mm upward, standard lengths typical per manufacturer)

Chemical Composition (Typical / Standard Limits)

Mechanical Properties

Main Characteristics

• Precision dimensional control: after welding, the tube is cold-sized (reduced) to tight tolerances in outer diameter, wall thickness, straightness, and roundness as per EN 10305-3.

• Good mechanical strength: 28Mn6 can deliver moderate to high strength, especially when heat-treated.

• Good formability: in softer conditions, it can be cold-formed, bent, or flanged.

• Weldability: acceptable weldability, though care must be taken in processing and potential post-weld treatment.

• Surface quality: a defined maximum surface roughness is required by the standard to ensure compatibility in precision applications.

• Versatility in heat treatment: it supports normalizing, quenching & tempering, annealing, providing flexibility to tailor property ranges.

Compliance / Applicable Standards

• EN 10305-3:2023 — Steel tubes for precision applications, technical delivery conditions for welded cold-sized tubes.

• Earlier versions: EN 10305-3:2016 / 2010 / 2002

• The tube must also satisfy general steel product delivery standards and reference standards such as EN 10020, EN 10021, EN 10027, EN 10204, EN 10266, and testing standards like EN 10246-3 (eddy current testing of tubes).

• The standard is applicable for outside diameter ≤ 193.7 mm (for circular cross-section) and can also be extended to square/rectangular tubes.

Application Domains

Broad Application Fields

This tube is suited for precision structural, mechanical, and assembly use in fields such as automotive systems, machinery, furniture frames, mechanical instrumentation, and assembly jigs.

Specific Use Cases

Q: Are you trading company or manufacturer ?

A: manufacturer,also can do trading.

Q: How long is your delivery time?

A: Generally speaking,it is 10-15 days if the goods are in stock,or it is 30-40 days if the goods are not in stock,

it is according to quantity.

Q: Do you provide samples? is it free or extra ?

A: Yes, we could offer the sample for free charge but need pay the cost of freight.

Q: What is your terms of payment ?

A: Payment<=2000USD, 100% in advance. Payment>=2000USD, 30% T/T in advance ,balance before shippment.

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