Metal expansion wall plugs with a 4 segment design, for light duty wood screw fixings into concrete, brick and aerated concrete block.
Products with the “To Order” icon may not always be available from stock for same-day or next-day delivery. Please contact our team, who will be happy to confirm exact delivery dates.
Metal expansion wall plugs with a 4 segment design, for light duty wood screw fixings into concrete, brick and aerated concrete block.
Products with the “To Order” icon may not always be available from stock for same-day or next-day delivery. Please contact our team, who will be happy to confirm exact delivery dates.
Metal expansion wall plugs are 4 segment plugs that open out as a wood screw is driven in, for light duty fixings into concrete, brick and aerated concrete block. Electricians, plumbers and maintenance teams use them where a metal fixing is needed or the wall is too soft for a plastic plug. Each size has published recommended loads for all three base materials.
In aerated block, a plastic plug often spins or pulls out because the material is too soft for it to bite. On site, that means loose clips and brackets, oversized holes and repeat call-outs. The four metal segments spread outwards as the screw goes in, so the plug locks into the hole wall in soft and hard materials alike.
4 segment expansion: four metal segments spread evenly as the screw is driven, gripping the hole wall on all sides.
Aerated block, brick and concrete: one plug covers all three base materials, with a recommended load published for each.
All-metal construction: a metal plug where a non-plastic fixing is required, for example as part of a cable support.
Wood screws: works with standard wood screws, so no special screw is needed.
Trades and roles
Electricians
Plumbers and heating engineers
Fire alarm and security installers
Carpenters and joiners
Maintenance teams
Industries
Construction
Housebuilding
Building services
Facilities management
Social housing maintenance
| Specification | Detail |
| Product name | Metal Expansion Wall Plugs - 4 Segment |
| Product code | MP0 |
| Product type | Metal expansion plug |
| Expansion | 4 segment, expanded by the screw |
| Screw type | Wood screws |
| Duty | Light duty |
| Base materials | Concrete, solid brick, aerated concrete block |
| Load test conditions | Concrete C20/25, brick 20 N/mm2, aerated block 3.5 N/mm2 |
| Product code | Size | Drill size | Hole depth | Min base thickness | Min spacing | Min edge distance | Fixture clearance hole | Screw diameter | Screw length | Rec. load, concrete | Rec. load, solid brick | Rec. load, aerated block |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MP06032 | 6mm x 32mm | 6mm | 40mm | 60mm | 110mm | 55mm | 6mm | 4.5mm to 5.0mm | Fixture thickness + 37mm | 0.22 kN | 0.17 kN | 0.07 kN |
| MP08038 | 8mm x 38mm | 8mm | 50mm | 70mm | 120mm | 60mm | 8mm | 5.0mm to 6.0mm | Fixture thickness + 43mm | 0.40 kN | 0.32 kN | 0.12 kN |
Size key: in 6mm x 32mm, the first number is the plug diameter, which is also the drill size. The second number is the plug length.
| Product code | Size | Drill size | Hole depth | Min base thickness | Min spacing | Min edge distance | Fixture clearance hole | Screw diameter | Screw length | Rec. load, concrete | Rec. load, solid brick | Rec. load, aerated block |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MP05030 | 5mm x 30mm | 5mm | 40mm | 60mm | 90mm | 45mm | 5mm | 4.5mm | Fixture thickness + 35mm | 0.20 kN | 0.16 kN | 0.06 kN |
| MP08060 | 8mm x 60mm | 8mm | 70mm | 120mm | 180mm | 90mm | 8mm | 5.0mm to 6.0mm | Fixture thickness + 65mm | 0.47 kN | 0.37 kN | 0.15 kN |
| Base material, use or condition | Suitability |
|---|---|
| Concrete | Suitable |
| Solid brick | Suitable, loads are guidance only |
| Aerated concrete block | Suitable, loads are guidance only, drill without hammer action |
| Wood screws | Suitable, use the screw diameter and length for the size |
| Dry internal conditions | Suitable |
| External or damp locations | Not recommended, no corrosion rating published, use a stainless steel fixing |
| Hollow brick and block | Not recommended, not a listed base material |
| Plasterboard | Not recommended, use a cavity fixing |
| Heavy or safety-critical loads | Not recommended, use an approved anchor with design data |
Electrical, mechanical and maintenance trades use metal expansion plugs on new build housing, refurbishment and commercial fit-out. Many fixings go into aerated block inner leaves and partitions, as well as brick and concrete. They are chosen where a plastic plug will not hold in soft block, or where the job calls for a metal fixing.
Fixing cable clips and metal cable supports where the installation calls for non-plastic fixings.
Fixing fire alarm devices, call points and sounders to aerated block and brick walls.
Fixing pipe clips and small brackets for plumbing and heating runs along aerated block walls.
Fixing consumer units, enclosures and back boxes to concrete and masonry.
Refixing loose fittings in aircrete walls where plastic plugs have spun out.
Step 1: Check the base material is at least the minimum thickness, and keep to the edge distance and spacing in the Size Selection table.
Step 2: Drill a hole the same diameter as the plug, to at least the hole depth for that size.
Step 3: Clear the dust from the hole.
Step 4: Push or tap the plug into the hole until it sits flush with the surface.
Step 5: Choose a screw length of fixture thickness plus the figure in the table, for example plus 37mm for the 6mm x 32mm plug.
Step 6: Hold the fixture in place and drive the wood screw into the plug until tight. Do not overtighten.
Using a screw that is too short, so the segments never fully expand.
Fixing too close to an edge or to another plug, which can crack brick and block.
Drilling aerated block with hammer action, which enlarges the hole and weakens the grip.
Treating the brick and block loads as exact, when they are guidance only.
Using metal expansion plugs for heavy or safety-critical loads.
Wear eye protection when drilling. Drilling concrete and masonry releases respirable crystalline silica dust, so use on-tool extraction and suitable RPE in line with HSE guidance. Keep within the recommended loads, and treat brick and block figures as guidance only. For heavy or safety-critical fixings, use an approved anchor with published design data.
Store plugs dry in their pack until use. Check fixtures during planned maintenance and refix any that have worked loose with a new plug.
Q: What load can a metal expansion wall plug hold?
A: The 6mm x 32mm plug has a recommended load of 0.22 kN in C20/25 concrete, 0.17 kN in solid brick and 0.07 kN in aerated block. The 8mm x 38mm plug has 0.40 kN, 0.32 kN and 0.12 kN. That is roughly 22kg to 40kg in concrete. Brick and block figures are guidance only, because these materials vary.
Q: What does 6mm x 32mm mean on a metal plug?
A: The 6mm is the plug diameter, which is also the drill size. The 32mm is the length of the plug. Drill to at least the hole depth for the size, which is deeper than the plug, so it sits flush.
Q: How long should the screw be?
A: Add the fixture thickness to the figure for the plug size. For the 6mm x 32mm plug, use fixture thickness plus 37mm. For the 8mm x 38mm plug, use fixture thickness plus 43mm. A shorter screw will not fully expand the segments.
Q: What are these plugs not suitable for?
A: They are not suitable for plasterboard, hollow walls, heavy items or safety-critical loads. They should not be used in base material thinner than 60mm for 6mm plugs or 70mm for 8mm plugs.
Q: Why choose a metal expansion plug over a plastic plug?
A: Metal segments bite into soft aerated block where a plastic plug can spin. A metal plug is also used where a non-plastic fixing is required. For light fixings in dense masonry, a plastic or nylon plug is usually enough.
Q: Can I use metal plugs to support cables under BS 7671?
A: BS 7671 requires wiring systems to be supported so they will not collapse prematurely in a fire, so plastic fixings cannot be the only means of support. Metal plugs with steel screws are commonly used for cable clips and supports for this reason. No fire test data is published for this plug, so confirm the support method against the installation design.
Q: How close to an edge can I fix?
A: Keep at least 55mm from an edge and 110mm between plugs for the 6mm x 32mm size. For the 8mm x 38mm size, keep 60mm from an edge and 120mm between plugs.
Q: Do metal expansion plugs rust?
A: No corrosion rating or finish is published for these plugs. Use them in dry internal conditions, and choose a stainless steel fixing for external or damp locations.
