Mild Steel Box Section 3m – S235 Square Hollow Section (SHS)

Our S235 mild steel box section is supplied in 3m lengths, in sizes from 20x20mm up to 150x150mm and wall thicknesses from 2mm to 5mm. The 3m length is easy to handle and transport, ideal for DIY, repairs, frames, shelving, gates and general fabrication, with a 3-5 working day lead time to mainland UK.

Technical Specification

Common Uses

Mild steel box section is widely used for frames, shelving, gates, railings, brackets, supports, trailers, workbenches, garden structures, workshop fabrication and general metalwork. The 3m length suits smaller projects and easier handling.

3m vs 7.5m Box Section

3m lengths are easier to handle, transport and ideal for DIY and smaller fabrication. 7.5m lengths suit trade and structural projects where fewer joints are an advantage. Both are supplied in the same S235 mild steel.

Finish and Protection

Supplied in standard mill finish. The surface may show normal mill scale, handling marks or light surface oxidation, typical for untreated steel. For outdoor or moisture-exposed use, clean, prime and protect with a suitable paint or coating system.

Cutting and Fabrication

S235 box section can be cut, drilled, welded and fabricated using suitable metalworking tools. Cut ends and drilled holes should be protected if used outside or in damp conditions.

Delivery Information

Lead times are currently 3-5 working days. Mild steel box sections are long, heavy items, so suitable delivery access is required. Offloading assistance may be required on site.

Frequently Asked Questions

What is steel box section used for?
Steel box section is a square or rectangular hollow section used for gates, railings, fencing, structural frames, support posts, trailers, shelving, balustrades, agricultural buildings, workshop fabrication and general construction. The hollow profile gives a high strength-to-weight ratio and is easy to weld, drill and fabricate.

What is the difference between SHS and RHS?
SHS (Square Hollow Section) has equal sides — 50x50mm, 80x80mm and so on. RHS (Rectangular Hollow Section) has unequal sides — 60x40mm, 100x50mm and so on. SHS gives equal strength in both axes and suits general-purpose frames and posts. RHS gives greater strength on the longer axis and is used for beams, lintels and load-bearing spans where strength is needed in one direction.

What does ERW mean on steel tube?
ERW stands for Electric Resistance Welded. It describes the manufacturing process where a flat steel strip is formed into a tube and the longitudinal seam is welded using electrical resistance. ERW is the standard process for structural hollow sections including box section, rectangular section and round tube.

What sizes do steel box sections come in?
Our mild steel box section range covers square sizes from 20x20mm up to 150x150mm in wall thicknesses from 2mm to 6mm, plus rectangular hollow sections. Supplied in 3m, 6m and 7.5m lengths depending on the product. Galvanised, aluminium and stainless steel box sections are also available.

Can steel box section be cut to size?
Box section is supplied in full stock lengths. As a structural steel section, it can be cut to length on site with an angle grinder, chop saw or bandsaw. For large quantities of identical cut lengths, contact us with your requirements.