Base for welding 42,4mm, Raw

The Strofix bottom fastening for welding is an AISI 304 stainless-steel cast round base plate for the Ø42.4 mm round railing post tube. The Ø100 mm flange has an open round aperture at the centre, reinforced by cast ribs. Supplied with a raw (unfinished) surface.

The post tube passes through the central aperture and is welded to the flange, giving a fully rigid post-to-base connection. The flange is then bolted to the floor, slab or substrate through the fixing holes around its edge. The cast ribs stiffen the plate against bending under post loads.

The raw surface finish is standard for welded base plates, which are typically concealed by a decorative cover after installation. AISI 304 stainless steel is suitable for standard interior and exterior installations.

Use cases:

• Welded floor mounting of Ø42.4 mm round railing post tubes to concrete slabs
• Structural post foundation for balcony and terrace railings
• Round post base for staircase railing installations
• Workshop prefabrication — weld post tubes to base plates before site installation
• Concealed base fixing under a decorative cover plate

FAQ:

What post tube does this base fit?

The central aperture takes the Ø42.4 mm round post tube. The tube passes through the flange and is welded to it.

What is the plate diameter?

Ø100 mm, with cast reinforcing ribs around the central aperture.

How is the post tube attached to the plate?

The post tube is welded to the base plate. TIG or MIG welding is required. This is a professional installation step, typically carried out in a workshop before site delivery.

Why is the surface finish raw?

Welded base plates have a raw (mill finish) surface because the weld itself is ground and finished on site, and because the plate is normally concealed by a decorative cover afterwards. The Strofix Covers category includes cover plates for both square and round post bases.

Is there a version that does not need welding?

Yes. The hammered base for the same Ø42.4 mm post tube has a collar formed from the flange and is supplied with a satin finish, so it can be left exposed.

About Base & Clamp Fastenings

A base or clamp fastening is a stainless-steel plate or bracket that anchors a railing post to the building structure, forming the structural foundation of the balustrade. Bottom fastenings bolt to the top of a floor slab, deck or beam, while side fastenings bolt to the vertical face of a fascia, edge beam or wall. Assembly clamps grip an existing tube or post without welding, and assembly plates provide a flat mounting surface for auxiliary connections.

Strofix supplies 18 base and clamp products for Ø42.4 mm round pipe and 40×40 mm flat-sided square posts, with plate diameters from Ø80 to Ø100 mm (round) and plate dimensions from 80×80 to 135×56 mm (rectangular/square), in satin or raw-surface stainless steel with AISI 304 and AISI 316 options.

Screw-hole configurations include 2, 3 and 4-hole variants. The correct fastening depends on mounting orientation, post profile, plate size, number of screw holes and the required surface finish.