Bottom fastening

The Strofix bottom fastening is an AISI 304 stainless-steel lightweight base plate for the 40 × 40 mm square railing post tube, available in three plate sizes: 105 × 105, 100 × 100, or 80 × 80 mm. All variants share a 4 mm plate thickness (h) and four bolt holes. The bolt hole diameter depends on the plate size: Ø9 mm (for M8 bolts) on the 105 × 105 and 80 × 80 mm plates, or Ø11 mm (for M10 bolts) on the 100 × 100 mm plate. Supplied with a raw (unfinished) surface. The post tube is attached by welding (elements for welding included).

The 4 mm plate thickness makes this the lightest and most economical base plate for the 40 × 40 mm post in the Strofix range. The three plate size options allow the installer to match the base plate to the available fixing area and the decorative cover size. The 80 × 80 mm plate provides the most compact footprint; the 105 × 105 mm plate provides the largest bearing area. Select the plate size in the dropdown at order time.

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

Use cases:

• Light-duty floor mounting of 40 × 40 mm square railing posts
• Budget-conscious railing installations requiring a simple base plate
• Compact 80 × 80 mm base plate where minimal footprint is needed
• Standard 100 × 100 or 105 × 105 mm base plate for residential railing systems
• Workshop prefabrication — weld post tubes to base plates before delivery

FAQ:

What plate sizes are available?

Three plate sizes: 105 × 105 mm, 100 × 100 mm, and 80 × 80 mm. Select in the dropdown at order time.

What bolt size does each plate accept?

The 105 × 105 and 80 × 80 mm plates have Ø9 mm bolt holes (for M8 bolts). The 100 × 100 mm plate has Ø11 mm bolt holes (for M10 bolts). All variants have four bolt holes.

What is the plate thickness?

All three plate sizes share a 4 mm thickness (h = 4 mm). This is the thinnest base plate in the Strofix range for this post tube.

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

The Strofix range includes three base plate options for the 40 × 40 mm square post. This lightweight version has h = 4 mm with three plate size options. The standard version has h = 6 mm with a 100 × 100 mm plate and 4 bolt holes. The heavy-duty version has h = 18 mm with a 100 × 100 mm plate and 2 bolt holes. Choose based on the required structural capacity and budget.

How is the post tube attached?

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

Why is the surface finish "raw"?

Base plates have a raw finish because they are typically concealed by a decorative cover after installation.

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.