300x300x6mm  Steel high-strength square tube S420MC, S500MC, S600MC, S700MC

300×300×6 mm S420MC–S700MC High-Strength Square Hollow Section

300x300x6mm Steel high-strength square tube in S420MC, S500MC, S600MC, S700MC to EN 10219 / EN 10149-2, with an uncoated steel surface suitable for further processing or painting. Nominal weight 54.662 kg/m.

Minimum order

Minimum 10 t per size. If the size is already in the current production cycle, we can accept orders from 5 t. Standard length 6 m; 4–12 m on request. We confirm the minimum, lead time and grade in your quote.

Add to Quote Request

Select length and quantity to add to your quote cart

Minimum order: 10 t per size (from 5 t if the size is in production)

Weight per meter:54.662 kg/m
Total length:6 meters
Total weight:327.972 kg

Applications & Usage

This heavy-duty structural Steel high-strength square tube is commonly specified for framework, support structures, machinery bases, and industrial equipment. The 6mm wall thickness provides superior load-bearing capacity while maintaining workability. The natural mill finish provides a cost-effective solution for applications where aesthetics are secondary. Available in standard lengths of 6m, this profile can be easily cut, drilled, and welded to suit your specific requirements.

Technical Specifications

SpecificationValue
Dimensions300mm × 300mm × 6mm
Weight per Meter54.662 kg/m
MaterialSteel
Alloy/GradeS420MC, S500MC, S600MC, S700MC
StandardEN 10219 / EN 10149-2
Standard Length6m
Minimum Order per Size10 t
Cut-to-Length Range4000 – 12000 mm

Section Properties

Nominal values calculated from nominal dimensions to EN 10219-2.

PropertyValue
Cross-sectional area(A)69.6 cm²
Second moment of area(I)9964 cm⁴
Radius of gyration(i)12.0 cm
Elastic section modulus(Wel)664 cm³
Plastic section modulus(Wpl)764 cm³
Torsional inertia constant(It)15434 cm⁴
Torsional modulus constant(Ct)997 cm³
Surface area per metre(As)1.18 m²/m
Length per tonne18.3 m

High-strength grades for this size

Strength and indicative capacity for each grade this size is rolled in, compared with the S355J2H wall that carries the same bending load in the same outer size.

GradeMin. yield ReHTensile RmBending Wel·ReHAxial A·ReHS355J2H equivalent
S420MC420 MPa480–620 MPa279 kNm2925 kN8 mm · 71.6 kg/m (+31%)
S500MC500 MPa550–700 MPa332 kNm3482 kN10 mm · 88.4 kg/m (+62%)
S600MC600 MPa650–820 MPa399 kNm4178 kN12 mm · 104 kg/m (+90%)
S700MC700 MPa750–950 MPa465 kNm4874 kN14 mm · 119 kg/m (+118%)

In S700MC, this section (54.7 kg/m) carries the elastic bending load of a 14 mm S355J2H wall in the same outer size (119 kg/m), which is 118% heavier per metre.

Indicative values from nominal dimensions: Wel × ReH and A × ReH, without buckling, cross-section class or partial safety factors. Not a design check.

Same size in S235JRH–S355J2H (EN 10219) →