How to choose
A practical sequence for matching the hole, plug, screw and substrate without relying on plug colour.
Quick answer
Use the fixing manufacturer table for the exact plug. The stated plug diameter normally determines the nominal drill size, while the approved screw range, embedment and substrate determine whether the complete system fits.
Scope: Confirm substrate, load direction, edge distances and maker data; safety-critical or structural fixings need competent design.
Four options to compare
Best for: A named plug or anchor with a current technical table for your substrate.
Main trade-off: You must follow the complete installation specification rather than substitute by colour or appearance.
Must check: Article number, substrate, drill diameter, screw range, depth and cleaning steps.
Best for: Low-consequence maintenance where the plug can be removed and identified.
Main trade-off: Reusing an unknown or damaged hole can reduce confidence.
Must check: Remove and replace with a documented system rather than guessing from colour.
Best for: A known board thickness and rear clearance using a purpose-designed fixing.
Main trade-off: A normal masonry plug may not form a reliable cavity fixing.
Must check: Board range, setting method, screw thread and rear clearance.
Best for: Heavy, overhead, cantilevered, safety-critical or valuable installations.
Main trade-off: A consumer compatibility checklist is not a structural design.
Must check: Use a competent specification and do not publish or rely on an unsupported load value.
Record the substrate, hole diameter and depth, exact fixing, approved screw and fixture thickness. If any one is unknown, the system is not yet checked.
Colours vary between brands and ranges. Match an article number and technical table, not a colour convention remembered from another product.
What this guide cannot check
Do not claim universal safety, guaranteed suitability, professional approval or permission to undertake protected work. Check current instructions, exact identifiers and local circumstances before acting.