Bottom fastening

The Strofix bottom fastening is an AISI 304 stainless-steel heavy-duty base plate for the 40 × 40 mm square railing post tube. The plate measures 100 × 100 mm (D), with an 18 mm thickness (h) and two 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 18 mm plate thickness is three times heavier than the standard 6 mm base plate for the same tube, providing substantially greater rigidity and load-carrying capacity at the post-to-floor connection. The two-bolt configuration concentrates the anchor forces into two fixing points rather than four, which may be preferred for specific structural configurations or where bolt spacing constraints limit the number of available anchor positions. The Ø11 mm bolt holes accept M10 bolts or anchor rods. The raw surface finish is standard for base plates 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, h = 18 mm, 2 bolt holes, AISI 304 only.

Use cases:

• Heavy-duty floor mounting for 40 × 40 mm square railing posts under high loads
• Post base connections requiring increased plate thickness for structural rigidity
• Two-bolt anchor configurations where 4-bolt patterns are not feasible
• Commercial railing installations with higher-than-standard post loading
• Glass balustrade systems with 40 × 40 mm posts carrying wind loads on glass panels

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 an 18 mm thickness (h). Two Ø11 mm bolt holes are positioned on a 74 mm pattern diameter (d).

How does this differ from the standard 40 × 40 mm base plate?

Both fit the same 40 × 40 mm post with a 100 × 100 mm plate and Ø11 mm bolt holes on a 74 mm pattern. The key differences are plate thickness (18 mm vs 6 mm) and number of bolt holes (2 vs 4). This heavy-duty version provides greater rigidity at the post base connection and is suited for higher-load applications.

Why only 2 bolt holes instead of 4?

The two-bolt configuration may be specified when the structural engineer determines that two anchor points are sufficient for the loading, or when site constraints limit the available anchor positions. The thicker 18 mm plate compensates for the reduced number of fixings by providing greater bending resistance.

What bolt size do the holes accept?

The Ø11 mm bolt holes provide clearance for M10 bolts or anchor rods.

How is the post tube attached to the plate?

The post tube is welded to the base plate using TIG or MIG welding.

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.