Bottom fastening

The Strofix bottom fastening is an AISI 304 stainless-steel base plate for the 40 × 40 mm square railing post tube. The plate measures 100 × 100 mm (D), with a 6 mm thickness (h) and four Ø11 mm bolt holes arranged on a 74 mm pattern (d). Supplied with a raw (unfinished) surface. The post tube is attached to the base plate by welding (elements for welding included).

The base plate is the structural foundation of the railing post. The 40 × 40 mm square post tube is welded to the top face of the plate, and the plate is then bolted to the floor, slab, or substrate using M10 anchor rods or bolts through the four Ø11 mm clearance holes. The 100 × 100 mm plate size provides a stable bearing area for the post loads. The raw surface finish is standard for base plates that are typically concealed by a decorative cover after installation. AISI 304 stainless steel is suitable for standard interior and exterior installations.

This SKU is a single fixed configuration — 40 × 40 mm post, 100 × 100 mm plate, AISI 304 only.

Use cases:

• Floor-mounting 40 × 40 mm square railing post tubes to concrete slabs
• Base plate for square post balcony and terrace railing installations
• Structural post foundation for staircase railing with square tube posts
• Bolted base fixing for square tube railing systems on balcony slabs, floors, and decks
• Workshop prefabrication — weld post tubes to base plates before site installation

FAQ:

What post tube does this base plate fit?

The base plate fits the 40 × 40 mm square post tube. The tube is welded to the top face of the plate.

What are the plate dimensions?

The plate is 100 × 100 mm (D) with a 6 mm thickness (h). Four Ø11 mm bolt holes are positioned on a 74 mm pattern diameter (d).

What bolt size do the holes accept?

The Ø11 mm bolt holes provide clearance for M10 bolts or anchor rods. Use with the Strofix M10 anchor rods, washers, and nuts from the Fastenings category.

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"?

Base plates have a raw (mill finish) surface because they are typically concealed by a decorative cover after installation. The Strofix Covers category includes cover plates for both square and round post bases.

Is a round tube base plate available?

Yes. The Strofix Base, clamp category includes base plates for Ø42.4 mm round post tubes as well as various other configurations for both tube profiles.

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.