Never use nylon wall plugs or plasterboard anchors for safety-critical fixings. Handrails, stair rails, banisters, balustrades, gates, ladders, climbing or play equipment, overhead fixings, and anything else whose failure could cause a fall or injury need a fixing designed and rated for that purpose — typically a through-bolt, a mechanical anchor or a resin-bonded anchor with a published load rating (and, for structural use, a European Technical Assessment). If you are not certain the wall and the fixing are up to the job, get advice from a builder or structural engineer.
Choosing the right wall plug, fixing, and drill bit combination is one of the most common DIY challenges in the UK. Get it wrong and your shelf collapses, your TV mount pulls out of the wall, or your curtain pole drops in the middle of the night. Get it right and your fixings will hold securely for decades.
This guide is the definitive UK resource for wall plug compatibility — covering every plug colour, the correct drill bit size for each, the right screw to pair with it, and which fixing type suits each wall material. Whether you’re hanging a heavy mirror on plasterboard or bolting a TV bracket into solid brick, you’ll find the answer here.
Quick Reference — Wall Plug Colour Chart
Every DIYer in the UK knows wall plugs come in different colours, but not everyone knows what those colours mean. Here’s the quick-reference chart you’ll want to bookmark:
| Plug Colour | Plug Size | Drill Bit Size | Screw Size | Application check |
|---|---|---|---|---|
| Yellow | 5mm | 5mm | As on the packaging | Check the exact product’s specified substrate and load. |
| Red | 6mm | 6mm | As on the packaging | Check the exact product’s specified substrate and load. |
| Brown | 7mm | 7mm | As on the packaging | Check the exact product’s specified substrate and load. |
| Blue | 8mm | 8mm | As on the packaging | Check the exact product’s specified substrate and load. |
| Grey | 10mm | 10mm | As on the packaging | Check the exact product’s specified substrate and load. |
Recommended Drill Bit Sets
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Colour is a maker’s convention, not a standard. This chart follows Rawlplug’s UNO range (yellow 5mm, red 6mm, brown 7mm, blue 8mm, grey 10mm). Other brands use different colours. Go by the diameter printed on the box or plug and drill to that size.
Get the free Drill Bit & Wall-Plug Size Chart (PDF)
Every drill size, wall-plug colour & tap size on one printable sheet.
Use the drill diameter and minimum hole depth specified for the exact plug. Colour and nominal diameter alone do not establish the required depth. Measure embedment into the load-bearing substrate and follow the manufacturer’s drilling and hole-cleaning instructions.
For the full detailed chart with load ratings, screw lengths, and pilot hole guidance, see our complete Wall Plug Size Chart.
Which Wall Type Do You Have?
Before choosing any fixing, you need to know what your wall is made of. The wrong fixing in the wrong wall type is the number one cause of failed mountings. Here’s how to identify your wall:
Solid Masonry (Brick, Block, Concrete, Stone)
The test: Knock on the wall — it sounds solid with no hollow echo. When you drill, you’ll get brick or concrete dust (red, grey, or white powder).
What to use: Standard nylon wall plugs (the coloured ones above) with masonry drill bits. Published plug loads in these walls are higher than in hollow or aerated materials (Rawlplug’s UNO card, for example), but the figure depends on the plug brand and the wall itself — see the substrate-by-substrate load table on our masonry wall plugs guide.
Full guide: Masonry Wall Plugs & Fixings — Complete Guide
Plasterboard (Drywall)
The test: Knock and you’ll hear a hollow sound. When you push a pin into the wall, it goes in easily. Drilling produces fine white dust.
What to use: Expansion-only masonry plugs are not a default plasterboard fixing. Some universal plugs are specified for plasterboard: Fischer lists DuoPower 8 × 40, article 535455, with a minimum panel thickness of 12.5mm. Select the exact fixing for the board construction, thickness and load, and follow its screw and installation requirements.
Full guide: Plasterboard Fixings Guide — Anchors, Toggles & Weight Limits
Cavity Walls (Plasterboard over Stud Frame, or Brick with Air Gap)
The test: Parts of the wall sound hollow (between studs) and parts sound solid (on the studs). Common in modern UK homes.
What to use: If you can hit a stud, screw directly into it. For hollow sections, use cavity wall fixings — spring toggles, hollow wall anchors, or umbrella bolts.
Full guide: Cavity Wall Fixings Guide — Spring Toggles, Hollow Wall Anchors & More
Fixing by Application
Sometimes you just need to know: what fixings do I need for this specific job? These guides give you the exact fixing type, plug size, drill bit, and screw for common UK household tasks:
| Application | Load to assess | Selection requirement | Guide |
|---|---|---|---|
| TV Wall Mount | Use the actual fixture and contents, including leverage. | Choose a documented fixing for the actual substrate and application; do not select by plug colour. | What Fixings for a TV Mount? |
| Curtain Poles | Use the actual fixture and contents, including leverage. | Choose a documented fixing for the actual substrate and application; do not select by plug colour. | What Fixings for Curtain Poles? |
| Heavy Shelves | Use the actual fixture and contents, including leverage. | Choose a documented fixing for the actual substrate and application; do not select by plug colour. | What Fixings for Heavy Shelves? |
| Heavy Mirrors | Use the actual fixture and contents, including leverage. | Choose a documented fixing for the actual substrate and application; do not select by plug colour. | What Fixings for Heavy Mirrors? |
Essential Tools for Any Fixing Job
Before starting any fixing project, make sure you have these essentials:
- Combi drill or impact driver: For driving screws. A cordless combi drill handles both drilling and driving — see our best battery for cordless drills guide.
- Masonry drill bits: Tungsten carbide tipped bits in 5mm, 6mm, 7mm, 8mm and 10mm cover the Rawlplug UNO sizes. Check price on Amazon
- Wall plug assortment kit: A mixed box of yellow, red, and brown plugs plus matching screws saves multiple trips to the hardware shop. Check price on Amazon
- Stud finder / detector: Essential for plasterboard walls — find studs, wires, and pipes before drilling. Check price on Amazon
- Spirit level: For ensuring brackets, shelves, and mounts are perfectly horizontal.
Watch: Video Guide
Frequently Asked Questions
What size drill bit do I need for a red wall plug?
For the 6mm red plug specified by the product range used here, follow the manufacturer’s 6mm drill requirement and its listed screw range. Confirm the exact product rather than relying on colour. A red plug is not automatically suitable for a shelf, curtain pole or other load.
Can I use wall plugs in plasterboard?
Expansion-only masonry plugs are not a default plasterboard fixing. Some universal plugs are specified for plasterboard: Fischer lists DuoPower 8 × 40, article 535455, with a minimum panel thickness of 12.5mm. Select the exact fixing for the board construction, thickness and load, and follow its screw and installation requirements. See our plasterboard fixings guide for full details.
How much weight can a wall plug hold?
There is no reliable load rating by plug colour or nominal diameter. Use the manufacturer’s recommended load for the exact plug, screw, substrate grade and installation conditions. We have withdrawn the earlier SX numeric examples because their product and table-column matching has not been established. Do not multiply a single-fixing figure by the number of fixings to calculate a safe shelf or bracket load. Further reading: masonry wall plugs guide.
What’s the difference between a wall plug and a Rawlplug?
Rawlplug is actually a brand name — “Rawlplug” became a generic term in the UK for any nylon wall plug, similar to how “Hoover” means vacuum cleaner. Plugs from different brands come in the same common diameters, but the colours do not line up: Rawlplug’s UNO blue plug is 8mm, other brands may use blue for a different size, and some brands use one colour for every size. Match the diameter printed on the plug, not the colour.
Do I always need a wall plug?
Not always. If you’re screwing into timber (like a stud behind plasterboard, a wooden door frame, or a timber beam), you can screw directly into the wood without a wall plug. Wall plugs are needed when screwing into masonry (brick, block, concrete, stone) because the screw alone can’t grip the hard material.
Wall Plug Compatibility Guides
Explore our complete range of fixing compatibility guides:
- Wall Plug Size Chart — The Definitive UK Reference
- Masonry Wall Plugs & Fixings Guide
- Plasterboard Fixings Guide
- Cavity Wall Fixings Guide
- What Fixings for a TV Mount?
- What Fixings for Curtain Poles?
- What Fixings for Heavy Shelves?
- What Fixings for Heavy Mirrors?
Essential Tools & Fixings
These are the products we recommend most across all our fixing guides. Every link below takes you to Amazon — if you buy through them, we earn a small commission at no extra cost to you.
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How we compile this guide
We cross-reference compatibility details against manufacturer specifications where available, official tool manuals, and the physical standards that govern fitment (bore sizes, arbor diameters, voltage platforms, connector types). We prioritise primary sources over retailer listings, flag anything we can’t confirm, and re-verify the data on a regular cycle. Where we give a buying recommendation, we tell you the reasoning — not just the link. More on our method →
