Wall plug drill size and screw size question

[john2k]

I’ve got the following wall plugs it the red 6mm one https://www.toolstation.com/rawlplug-uno-universal-contract-wall-plug/p49379

Does this mean I need to use a 6mm drill bit to make the hole? Also what sort of size diameter and length screw works with this size wall plug? How does one determine size of screw?

Thanks

 

[pete01]

5.5mm drill bit

2 inch 10 screws

Thats what I use anyway for most things.

 

[blackworx]

A 6mm wall plug will usually require the use of a 6mm masonry drill bit, with your drill on the hammer setting.

You can use 3 to 5mm diameter screws, although 4mm will be best. 3mm can be too loose, and 5mm can be so tight that it will start to spin the plug, which will prevent you from fully tightening the screw.

If the masonry is quite loose/powdery (and very easy to drill into) you might be better off with a 5.5mm drill. You can always drill a 5.5mm hole to begin with, then expand it to 6mm if the plug wont fit. It's ok to use a hammer to tap the plug home but be careful not to damage the wall. The tighter the fit of the plug in the hole, the better.

The depth of the hole you drill should be at least equal to the length of the plug, but should generally be a little longer.

The length of the screw should usually be at least equal to the length of the plug plus the thickness of whatever is being screwed to the wall, but can be a little shorter. You are aiming to fill as much of the plug with screw as possible. If it is longer (which is fine) be aware that you'll need to drill a deep enough hole to accommodate the screw sticking out the end of the plug inside the hole.

 

[johnny2007]

The length of the screw should usually be at least equal to the length of the plug

Don't know about cheap plugs, but Fischer recommends length of screw to protrude 10mm out of the plug on final installation.
So with a 40mm plug and screw going flush to the wall, you'd need a 50mm screw.