Base plates

What does a base plate do?

A base plate is the steel plate at the foot of a railing post. The post is welded to it or set into its socket, and the plate is bolted to the floor. It carries the load from the handrail into the slab, so the plate size, its thickness and the number of anchors decide how firmly the post stands.

Every plate in this category mounts on top of the surface – floor slab, stair tread or deck. To fix a post to the edge of a slab instead, see side mounting of the post. Assembly clamps are there too.

Which base plate fits my post?

Start with the post profile. Square plates are for 40x40 mm profile posts, round plates for Ø42.4 mm tube posts.

• Base plates for 40x40 posts – square weld-on plates from 80x80 to 105x105 mm
• Base plates for Ø42.4 posts – round weld-on plates from Ø80 to Ø100 mm
• Cast bases – heavier 100x100 mm and Ø100 mm bases for both profiles, raw for welding or satin with a formed socket

Then choose the plate size and the number of holes. A larger plate with four anchors spreads the load over more of the slab. A smaller plate with two anchors fits narrow stair treads and places with little room.

For the whole system – posts, infill and handrail – read our guide Railing systems: how to choose the right solution for your balcony, terrace or stairs.

Base plate sizes, thickness and holes

Every base plate in the range:

Which anchors do the holes take?

The hole diameter sets the anchor size:

• Ø8.5 and Ø9 mm holes – M8 anchors
• Ø11, Ø12 and Ø12.5 mm holes – M10 anchors

Anchor bolts and screws are in anchors, screws, and resin for chemical anchoring in chemistry, adhesives.

Weld-on plate, cast base or socket base?

The three types differ in how the post is joined to the plate.

Raw or satin – do I need a cover?

Raw plates are made to be welded and then hidden. A cover at the foot of the post hides the plate, the weld and the anchor heads.

Choose a cover larger than the plate:

• 40x40 mm posts – 90x90 mm covers, for plates up to 85x85 mm
• Ø42.4 mm posts – Ø85, Ø95 and Ø105 mm covers, for the Ø80, Ø93 and Ø100 mm plates

Satin socket bases are finished like the rest of the railing and can stay visible.

AISI 304, AISI 316 or S235?

• AISI 304 – standard stainless steel, for most indoor and outdoor railings
• AISI 316 – stainless steel with molybdenum, for coastal air, pools and de-icing salt. Available on the 85x85x6 mm and 105x105 mm plates for 40x40 posts, and as an option on the Ø93 mm plate
• S235 – carbon steel, not stainless. The 85x85x5 mm plate is for welding to a steel structure that is painted afterwards

Questions about base plates

Can a base plate go on a stair?

Yes. Fix the plate on the tread, not on its nosing, and keep the anchors well clear of the edge. Where the tread is too narrow for the plate, fix the post to the side of the stair with a side mount.

What is the difference between a base plate and an assembly clamp?

A base plate is a permanent fixing: the post is welded to the plate and the plate is anchored to the floor. An assembly clamp grips a post without welding. Assembly clamps are in side mounting of the post.

Do you have other plate sizes?

The plates in stock are listed above. For a different size or hole pattern, write to us with the post profile and the floor it goes on. We reply with a solution and a price, usually within one working day.