End cap for weld 40x40x4mm, hole ø12mm, RAW

The Strofix end cap for weld 40×40×4mm, hole ø12mm, RAW is an AISI 304 stainless-steel closure plate for the end of a 40 × 40 mm square railing tube. The 4 mm plate has a central Ø12 mm hole and is welded over the tube end, sealing the open section while allowing a bolt or rod to pass through the hole. Supplied with a raw (unfinished) surface.

This weld-on end cap closes the open end of a 40 × 40 mm square tube and is fixed by welding rather than press-fitting or bonding, giving a permanent, flush closure for fabricated steel assemblies. The central Ø12 mm hole is larger than the Ø8 mm version, accepting a larger through-bolt, threaded rod, or M12 fixing. The raw surface is intended to be ground and finished or coated on site after welding.

Use cases:

• Welded closure of a 40 × 40 mm square railing tube end
• Permanent flush end closure in fabricated steel assemblies
• Tube-end cap with a Ø12 mm hole for a larger through-bolt or threaded rod
• Raw-surface cap for grinding and finishing on site after welding
• Stainless-steel weld-on end cap for square railing tube

FAQ

How is this end cap fixed?

By welding. It is welded over the end of a 40 × 40 mm square tube, giving a permanent closure — unlike the press-fit or threaded caps, which insert into the tube.

What is the Ø12 mm hole for?

It allows a larger bolt or threaded rod (such as M12) to pass through the cap. The Ø8 mm and Ø16 mm hole versions are also available.

What tube does it fit?

A 40 × 40 mm square tube.

Why is the surface raw?

The raw finish is intended to be ground and finished or coated on site after welding, to match the surrounding metalwork.

What steel grade is used?

AISI 304 stainless steel, raw surface.

About End Caps

An end cap is a stainless-steel closure piece that plugs into or fits over the open end of a railing tube, post or solid bar, sealing it against moisture ingress and giving the termination a clean, finished appearance. Without an end cap, the cut tube end is exposed — visually unfinished and prone to collecting water and debris inside the hollow section.

Strofix supplies 13 end cap products in three profile families: caps for Ø42.4 mm round pipe (available in flat, convex and ellipsoid shapes), caps for 40×40 mm flat square tube (flat profile), and caps for Ø10 and Ø12 mm solid crossbar rods.

All are in AISI 304 stainless steel with a satin finish, with AISI 316 and polished options available on selected variants. The correct end cap depends on the tube or rod profile it will close, and the desired cap shape.