No - there is nothing solid for it to press against, so it spins or pulls straight out.

The plug works by being compressed against the wall of the hole. In a thin board with a void behind, most of the plug is in free air.

What usually happens is that the plug rotates with the screw, chewing the board around the hole until nothing is left.

This is the single most common wrong-anchor mistake, because a lined wall can feel solid to knuckles.

Drilling a small pilot and reading the dust and resistance identifies the substrate in seconds.

In plasterboard, a toggle, hollow-wall anchor or self-drilling anchor is the correct choice.

Because expansion is the whole mechanism, and the hole sets how much expansion there is.

An oversized hole leaves the plug expanding into space rather than pressing on the wall, and the fixing pulls out under modest load.

An undersized hole forces the plug in distorted, so it grips unevenly and often damages the surface as it goes.

The correct diameter is printed on the packaging and is not negotiable.

Worn masonry bits cut oversize, sometimes by enough to matter, so the state of the bit is part of the specification.

Hole depth should exceed the plug length so dust has somewhere to go and the plug can seat fully.

The diameter and type the plug is designed for, long enough to expand the whole plug body plus the thickness being fixed.

The screw expands the plug progressively as it advances, so it must reach at least to the far end of the plug.

A screw that stops short expands only the mouth, and the fixing relies on a fraction of the plug.

Too thin a screw does not expand the plug enough; too thick can split it.

Thread form matters - plugs are generally designed around a coarse screw thread rather than a machine thread.

Packaging usually states both the plug's screw size range and the drill diameter, and both should be followed.

The wings stop the plug rotating, and the collar stops it being pushed too deep.

In semi-solid or friable material the plug tends to turn with the screw instead of expanding, which destroys the hole.

Wings or fins bite into the hole wall on insertion and resist that rotation.

The collar at the mouth sits against the surface and prevents the plug disappearing into a void behind a thin skin.

Both features add length at the face, so the fixture must accommodate the collar or the hole must be countersunk.

In clean, dense masonry neither is necessary and a plain plug performs the same.

Poorly - the material crumbles under expansion pressure, and a purpose-made anchor is the correct answer.

Aerated blocks are strong in compression as a wall and weak locally, so the concentrated outward pressure of a plug simply crushes the cells around it.

The symptom is a fixing that feels tight and then loosens permanently under a small load.

Anchors made for these materials cut a large helical thread and spread load over a much longer engagement instead of expanding.

Chemical anchors with sleeves are the other established answer for hollow and lightweight units.

Identifying the block type before drilling saves the trial and error, and the dust colour and drilling resistance usually reveal it.

The screw comes out easily; the plug generally stays in the wall and should not be reused.

A plug that has been expanded once has taken a permanent set and will not grip the same way again.

Refitting the same screw into an existing plug is usually fine, since the plug is already formed to it.

Pulling a plug out of the hole normally damages the hole mouth, and the plug itself.

Where the plug will not come out, it can be pushed in flush and filled over.

A fixing point that will be reused repeatedly is better served by a threaded insert or an anchor designed for that.

Yes - nylon is the general choice, polypropylene is cheaper and softer, and each behaves differently in hard and soft substrates.

Nylon is tough and resilient, grips well in dense material and tolerates a slightly imperfect hole.

Polypropylene is softer and more prone to deforming rather than expanding under the screw.

Nylon absorbs moisture and swells slightly, which in most fixings is neutral or helpful.

Temperature matters at the extremes: plastics soften with heat, so plugs are not the answer near heat sources.

For anything approaching a structural duty, a metal expansion anchor or a chemical anchor should be used rather than a plastic plug.