Structural hollow sections

Hybox® cold formed high-grade hollow sections

Hybox® is a cold formed, high-grade multi-purpose hollow section, offering trusted formability and toughness. It is batch-tested for your assurance and perfect for projects where you require guaranteed minimum strength and mechanical properties. It can be used in a wide range of structural and engineering applications, including all those where specific properties and compliance with design codes are required.

Hybox® fully complies with the European Standard for cold formed structural hollow sections, EN10219 S355 J2H and is used in a wide range of construction and mechanical related applications including wind bracing and machinery.

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Product specification

EN-Construction-Product-Hybox cold formed high-grade hollow sections-default

Hybox cold formed high-grade hollow sections

Specification details

EN-Construction-Product-Hybox cold formed high-grade hollow sections | Key product features

Key product features

Hybox® 355 - Cold formed structural hollow section

Key product features:

Excellent quality, made with steel from a high quality production process
Minimum strength of 355 N/mm²
Properties suitable for low temperature applications (27J @ -20°C)
Dimensional consistency and corner radius controlled
High levels of formability and, because the steel is fully-killed, excellent weldability
Suitable for applications demanding specific properties
Suitable for structural applications and fully compliant with design codes
Batch-tested to give the properties of the specific delivered material; full test certification supplied
Clearly marked as Hybox 355, with the reassurance of batch traceability
Specific technical support available
Excellent supply availability through approved stockholders
All Hybox 355 material is CE marked and is fully compliant with the Construction Products Regulation (CPR)
Suitable for galvanising

EN-Construction-Product-Hybox cold formed high-grade hollow sections | Mechanical properties

Mechanical properties

Yield strength R_eH min N/mm²	Tensile strength R_m min N/mm²		Elongation % min L₀ = 5,65 √S₀specimen	Impact strength 10mm x 10mm		Carbon equivalent (CEV) max
T≤16mm	T < 3mm	3mm≤T≤40mm	T ≤ 40mm	ºC	J
355	510-680	470 - 630	20	-20*	27	0.45

* For section sizes D/T < 15 (circular) and (B+H)/ 2T < 12.5 (square/rectangle) min elongation is reduced by 2%.

Chemical composition
% by mass

C	Si	Mn	P	S
0.22	0.55	1.60	0.030	0.030

Hybox® 355 is produced from fully killed steel - critical to formability and weldability.

EN-Construction-Product-Hybox cold formed high-grade hollow sections | Dimensional tolerances

Dimensional tolerances

Dimensional capability

Hybox® 355 are available in sizes from 26.9 x 2.0 OD up to and including 508.0 x 16 OD in our circular hollow sections range and from 25 x 25 x 2.0 up to and including 300 x 300 x 12.5 and the equivalent rectangles in our rectangular hollow section range.

Hybox 355 is supplied with a test report 3.1 to EN10204. Standard lengths are 7.5 metres and 12.0 metres, with special mill lengths from 6 metres up to 18m available by arrangement.

Further details of specific size and grade combinations are available upon request.

Dimensional tolerances

Dimensional tolerances are in accordance with EN10219: Part 2

	Circular	Square / Rectangular - Side length (mm)	Square / Rectangular - Tolerance
Outside dimension (D B and H)	±1% with a min of ±0.50mm and a max of ±10mm	H,B < 100 100 ≤ H,B ≤ 200 H, B > 200	±1% with a min of ±0.5mm ±0.8% ±0.6%
Thickness (T)	For D ≤ 406.4mm T ≤ 5mm ±10% T > 5mm ±0.50mm	T ≤ 5mm T > 5mm	±10% ±0.50mm
Out of roundness (O)	For D > 406.4mm ±10% with a max of ±2mm 2% for D/T < 100, where D/T ≥ 100 out of roundness tolerance to be agreed	-
Concavity/ Convexity (independent tolerance on outside dimensions)	-	Max 0.8% with a min of 0.5mm
Squareness of side	-	90º ± 1
External corner profile (radius need not be tangential to the sides) EN10219: Part 2 Table 3	-	T ≤ 6.0 6.0 < T ≤ 10.0 T > 10.0	1.6T to 2.4T 2.0T to 3.0T 2.4T to 3.6T
Twist (V)	-	2mm plus 0.5mm/m length
Straightness	0.20% of total length & 3mm over any 1m length	0.15% of total length & 3mm over any 1m length
Mass (M)	±6% on individual lengths	±6% on individual lengths
Length	-0 +50mm	-0 +50mm

EN-Construction-Product-Hybox cold formed high-grade hollow sections | Declaration of Performance

Declaration of Performance

Download Declaration of Performance (DoP) below:

EN-Construction-Approval_or_Certificate-Hybox 355J2H Declaration of Performance

Hybox® 355J2H DoP

Approval or Certificate

English

TST Hybox355J2H_CE+UKCA_UK_20210920.pdf235.29 KB

EN-Construction-Approval_or_Certificate-Hybox 420MH Declaration of Performance

Hybox® 420MH declaration of performance

Approval or Certificate

English

Hybox 420MH Declaration of Performance.pdf82.78 KB

EN-Construction-Product-Hybox cold formed high-grade hollow sections | Design data

Design data

Design data for structural hollow sections

**The essential aid for the design of steelwork**

Comprehensive section property data is provided in this ‘blue book’ as well as tables of member resistances, which are given for both Celsius® and Hybox® structural hollow sections. This enables rapid selection of steel members in compression and bending. Tables are also provided for combined bending and compression, web resistance and shear resistance. This edition provides resistances in accordance with Eurocode 3 together with the relevant UK and German National Annexes, as well as resistances to BS 5950.