Bottom fastening

The Strofix bottom fastening is an AISI 304 stainless-steel base plate for the 40 × 40 mm square railing post tube, with a fixed 87 × 87 mm plate size (D). The plate has a 4 mm thickness (h) and four Ø11 mm bolt holes for M10 bolts. Supplied with a raw (unfinished) surface. The post tube is attached by welding (elements for welding included).

The 87 × 87 mm plate provides a mid-size footprint between the compact 80 × 80 mm and standard 100 × 100 mm base plates in the Strofix range. This size may be specified to match a particular cover plate dimension, to fit a specific on-site clearance constraint, or where the structural design calls for a plate slightly larger than 80 × 80 but smaller than 100 × 100. The four M10 bolt holes provide a secure four-point anchor pattern. The 4 mm plate thickness and four-bolt configuration place this product in the lightweight tier of the 40 × 40 mm base plate range. AISI 304 stainless steel is suitable for standard interior and exterior installations.

The raw surface finish is standard for base plates concealed by a decorative cover after installation.

Use cases:

• Floor mounting of 40 × 40 mm square railing posts where an 87 × 87 mm footprint is specified
• Base plate installations where 80 × 80 is too compact and 100 × 100 is too large
• Matching a specific decorative cover plate size that requires an 87 × 87 mm base
• Residential railing installations with mid-size base plate requirements
• Four-bolt M10 anchor configurations on the 87 × 87 mm plate footprint

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 87 × 87 mm (D) with a 4 mm thickness (h). Four Ø11 mm bolt holes accept M10 bolts.

Why the 87 × 87 mm size?

The 87 × 87 mm plate sits between the 80 × 80 and 100 × 100 mm options available on other Strofix base plates. This size may be specified to match a particular cover plate or installation clearance requirement.

How does this compare to other 40 × 40 mm base plates?

This product has the same 4 mm thickness and 4×ø11 bolt holes as the 100 × 100 mm variant on the multi-size lightweight base plate (SKU SP-4010544). The difference is the fixed 87 × 87 mm plate size. Choose based on the required plate footprint.

How is the post tube attached?

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

What bolt size do the holes accept?

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

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.