Stair tread bolt Set 5B XXL, T=133 mm, for mortar anchoring

Stair tread bolt Set 5B XXL – side fixing with a drilled recess

LamiFIX stair tread bolt Set 5B XXL fixes treads with a drilled recess to the wall at the sides. The connector is inserted into the hole in the tread. A cover cap closes the fixing point for a neat finish.

Version B is also suitable for winding stairs. Each tread can be removed individually, making replacement or later work on the stairs easier.

Application and design

Set 5B XXL is designed for mortar anchoring in brick, concrete, calcium silicate brick and rubble masonry. This version has no acoustic isolation. The INOX Decor cover cap is included in the Set; matching solid wood cover caps are available separately.

Accurate drilling for a precise fit

Our drill bushes guide the drill bit accurately in angle and position throughout the drilling depth. Predrill at Ø16 mm with light hammer action, then finish at Ø20 mm without hammer action to avoid breaking the internal webs of the brick. Tip: rebar drill bits are particularly suitable for drilling brick without hammer action. Please consult us for insulating and lightweight blocks.

For accurate drill guidance, we lend matching drill bushes free of charge for up to three months. Installation using drill bushes is shown in the LamiFIX catalogue on page 26 . Matching drill bits are available separately.

Matching installation accessories

The Ø38 mm carbide boring bit, LF 2011.380.3, for drilling the tread recess is available separately. Matching wooden cover caps are offered in maple (LF 1436.009.1), beech (LF 1436.004.1) and oak (LF 1436.010.1).

Installation tip: fit treads from top to bottom

This keeps the fixing screws underneath the treads accessible.
Clean the holes and insert the mesh sleeves. Then install each tread individually:

1. Fill the mesh sleeve with mortar from back to front: 1/9 cartridge per Set.
2. Insert the anchor with a twisting motion to distribute the mortar around it.
3. The easiest method is to fit the wooden tread or a temporary tread immediately and screw it to the anchor while the mortar is still workable.

At 20 °C, our mortar provides approximately two minutes more working time than a high-speed mortar – enough to install one tread.

Required quantity per Set

• 1 XXL type A/B stair anchor, T=118 mm, M10, LF 3623.112.1, zinc-plated steel with INOX Decor cover sleeve
• 1 LamiFIX M10 connector, LF 35.M10x30 (catalogue LF 1035.130)
• 1 hex head screw 6.3 × 32 mm, LF 1560.003.1
• 1 INOX Decor cover cap, LF 1435.001.1
• 1 mesh sleeve Ø20 × 130 mm, LF 1710.021.1
• 1 wall rosette, LF 1801.025.1
• 1/9 cartridge of anchoring mortar LF 1720.002.1
• 1/5 adjustment washer LF 3605.002.1 for an 18–24 mm gap; each whole washer includes 1 long cover sleeve LF 3601.001.1 (26 mm)
• 1/100 threadlocker LF 3806.243.1

Ordering and sales units

The component list shows the quantities required per Set. Screws are supplied in packs of 100, mortar in whole cartridges and threadlocker in whole tubes; adjustment washers are sold individually.

Article number: LF 3623.225.4
XXL version, drilling depth 133 mm.