Length of screw for wall plug

DonnyDave

Should the tip of the screw protrude from the end of the wall plug or not? Should the tip protrude so that the full thickness of the screw is pushing against the end of the plug?

southcoastrgi

what colour rawplug & what are you trying to fix ?

SailorSam

http://www.youtube.com/watch?v=voC4AB0_pkI

DonnyDave

southcoastrgi wrote: »

what colour rawplug & what are you trying to fix ?

I've already done it but ask for future reference.

I fixed some plastic trunking with Plasplugs wallplugs which are suitable for 6, 8, 10 and 12 screw sizes. The plugs are 3mm long. I used a 6mm drill bit which is what it says on the Wilko branded cardboard sleeve. This is into plastered brick.

I used 1½ x 8g countersunk screws which I reckon might protrude a mm or so.

Obviously the objective is to get the wallplug to open up and push against the inside of the hole. A screw that is quite a bit longer than the plug won't give any benefit (along the additional length). However, if it isn't long enough then presumably it won't have the desired effect of opening up the plug. So how long is "long enough"?

DonnyDave

SailorSam wrote: »

http://www.youtube.com/watch?v=voC4AB0_pkI

Thanks. I already watched that video.

I am specifically interested in learning of how long the screw thread should go into the plug.

Is it OK for it to go on further? If it stops short, how short can it be before it causes the plug not to grip? (I appreciate that different plugs are designed differently and so there may not be a stock answer.)

tlh858

In a perfect world, the screw should go into the plug for the full length of the plug, not more or less.
The hole in the wall should also be the same depth as the plug.
In reality, a couple of mm either way won't make any difference.

The length of the screw is therefore selected based on the length of the plug plus the thickness of the material being fixed.

tom15387202

You should really drill the hole slightly deeper than the actual length of the wall plug.

This allows any debris not removed when drilling the hole to be pushed behind the plug and the extra depth stops the plug not fittng all the way in because of the dust.

cyclonebri1

tom15387202 wrote: »

You should really drill the hole slightly deeper than the actual length of the wall plug.

This allows any debris not removed when drilling the hole to be pushed behind the plug and the extra depth stops the plug not fittng all the way in because of the dust.

At least someone has the answer that everyone can understand:A:A:A

My view;

The plug should be correctly sized for the screw and the hole, oooooooooooh matron what does that mean?

It means, the screw must be able to support that that it is required to support.
Look at what any manf supply's with thier kit and use the next size up;);)

The plug must be able to accept the screw as determined above.

Bbuuuuuuuuuuutt, it is all dependant on the substrate, the wall or whatever.

So in practise on a bric/block wall, drill 1/2 to 3/4" deeper than the screw dictates, this ensures all said above by **** and means that the screw length is less important provided it isn't tooo short.

But again the other question is should the plug be flush to the surface or punched well into the wall where it can gain some grasp?
Guess.

soathcoast guy will understand but some folks still try to fix wall plugs into plasterboard