# SSAB Strenx Tube 960MH

Product-specific mechanical tests, section availability, welding-temperature controls and galvanizing limits for the cold-formed structural tube.

Reviewed: 2026-11-01

Tags: materials, steel, hollow-sections, producer-products

## Product identity

SSAB lists **40 J at −20°C** for **Strenx Tube 960MH**, transverse Charpy V on a **10 × 10 mm** basis, with testing from **6 mm wall**. Its welding guide gives **100°C maximum recommended preheat/interpass** and recommends **1–15 s t8/5** for the group containing 960MH. Determine minimum preheat and the qualified joint cycle separately. [SSAB 960MH impact footnote](https://www.ssab.com/en/brands-and-products/strenx/product-offer/tube/960-mh), [SSAB tube welding guidance](https://www.ssab.com/-/media/files/en/strenx/420-en-welding_of_strenx-v1-2026-consid_ab-a4-web.pdf?m=20260220080427)

**Strenx Tube 960MH is SSAB's high-frequency-welded, cold-formed structural hollow section made from hot-rolled high-strength steel.** The producer states that it meets or exceeds **EN 10219-3 (2020)**. Keep the complete designation separate from 960MC sheet and Tube 960QLH. [SSAB: Tube 960MH](https://www.ssab.com/en/brands-and-products/strenx/product-offer/tube/960-mh)

The product page lists circular diameters **139.7–219.1 mm**, square sections **100 × 100–200 × 200 mm**, rectangular sections **120 × 80–250 × 150 mm**, and walls **4–6 mm**. Confirm the offered size–wall combination rather than assuming every combination exists. [SSAB: dimensions](https://www.ssab.com/en/brands-and-products/strenx/product-offer/tube/960-mh)

## Mechanical tests and their limits

| Quantity | Product-page requirement |
| --- | --- |
| Minimum Rp0.2 | 960 MPa |
| Tensile strength Rm | 980–1250 MPa |
| Minimum A5 elongation | 6%, subject to section-proportion exception |
| Transverse Charpy-V | 40 J at −20°C, full-size 10 × 10 mm basis |

Elongation reduces by two percentage points for D/T < 15 or (B + H)/(2T) < 12.5. Rectangular specimens come from the longer side. Impact testing applies at **≥6 mm** under EN ISO 148-1. [SSAB: properties and footnotes](https://www.ssab.com/en/brands-and-products/strenx/product-offer/tube/960-mh)

## An application example, not a component approval

SSAB's rear-underrun-protection page lists **120 × 80 × 4 mm rectangular Tube 960MH** among sections for that application. It separately lists Tube 960QLH under EN 10210, showing why suffix and manufacturing route belong in the material record. This is an application lead, not proof that any proposed guard geometry, mounting or vehicle installation has passed its required assessment. [SSAB: rear impact guard material examples](https://www.ssab.com/en-us/brands-and-products/strenx/trailers/rupd)

For a proposed replacement, compare the original and revised section, attachments, load path and manufacturing condition. Do not substitute solely because one material has a higher nominal strength. Identify the evidence needed for the finished system before releasing the material change.

## Welding: minimum and maximum temperature are different controls

SSAB's **Welding of Strenx, V1 (2025)** lists **100°C maximum recommended preheat/interpass temperature for Tube 960MH**. It explains that the maximum protects the completed structure's mechanical properties. This is not a universal target preheat or a continuous service rating. [SSAB: welding guide, p. 17](https://www.ssab.com/-/media/files/en/strenx/420-en-welding_of_strenx-v1-2026-consid_ab-a4-web.pdf?m=20260220080427)

The same guide treats minimum preheat, heat input, joint/material combination and consumables as linked decisions. It lists a **1–15 s recommended t8/5 cooling-time range** for the group including Tube 960MH; that interval concerns cooling from 800 to 500°C, rather than total fabrication time. Its unalloyed/low-alloyed consumable guidance requires **≤5 ml hydrogen per 100 g weld metal**. [SSAB: welding guide, cooling and consumables](https://www.ssab.com/-/media/files/en/strenx/420-en-welding_of_strenx-v1-2026-consid_ab-a4-web.pdf?m=20260220080427)

Use the actual procedure and guide conditions to determine how the controls fit together. A maximum temperature cannot resolve a minimum-preheat requirement by itself. Obtain producer/welding-engineering advice where a proposed procedure cannot satisfy the necessary conditions.

Qualify joint preparation, consumables, shielding, heat input, temperature measurement, weld sequence and acceptance. Inspect the completed joint and heat-affected region against the drawing's requirements; the parent tube's tensile result does not qualify weld metal or an attachment detail. Retain seam orientation and traceability where cutting and assembly would otherwise obscure them.

## Surface protection and fabrication history

SSAB explicitly **does not recommend hot-dip galvanizing Tube 960MH**. Do not transfer a galvanizing instruction from another hollow-section grade. Agree an appropriate corrosion-protection system for this product and assembly. [SSAB: fabrication recommendation](https://www.ssab.com/en/brands-and-products/strenx/product-offer/tube/960-mh)

Include internal surfaces, drainage, access for preparation and repair requirements in that decision. Specify the actual coating route and curing exposure before production. A coating description does not settle the effect of heating, local straightening or repair welding on the steel.

For holes, end connections and fitted sleeves, assess outside dimensions, wall, corner geometry, straightness, seam and cut quality together. A sharp-corner CAD section is an approximation of supplied tubing. Define inspection locations and support conditions, and distinguish incoming tube tolerance from the welded assembly's final tolerance.

## Fatigue, inspection and release

SSAB's fatigue guidance explains that welded-detail behavior depends strongly on weld geometry, imperfections and residual stresses. Higher base-material strength alone does not establish a proportional improvement in welded fatigue life. Its trailer discussion also notes that reducing thickness increases working stress. Treat those examples as explanatory, then assess the actual member and load spectrum. [SSAB: fatigue guidance](https://www.ssab.com/en/support/how-to-design/trailer-design/design/fatigue)

A practical release record connects the order and material certificate to the section used, applicable test footnotes, approved fabrication route and final inspection. Preserve any repair history, thermal exposure, corrosion-protection requirements and in-service inspection plan. Resolve substitutions before fabrication rather than accepting a similar number in a trade name.

## Source versions

The A4 welding guide prints **420-UK, V1 2025**. The live product, application and fatigue pages do not establish technical revision dates here. The product page's EN 10219-3 (2020) reference is a cited specification edition, not this wiki's review date. Obtain current controlled supply documents and applicable design requirements for an actual order.

[Stock forms and dimensions](../stock-forms/index.md)