John Edgar wrote in message ...
I simply do not understand the science of drilling holes in walls and
then getting the right-sized plug to fit.
Assuming you're using size 8 screws, you really need masonry bits on hand of
5mm/5.5mm/6mm and 3 sizes of plug. In soft stuff the 5mm bit may bash a 6mm
hole and the red plastic plug will fit perfectly. In hard stuff the 6mm
drill hole will be precisely 6mm and the red plug will also fit perfectly.
Usually it's somewhere between the 2, which is where the 5.5mm comes in.
If the red plug is a sloppy fit, tap the small (usually yellow) plug inside
the red. If that's too tight, yellow in brown is worth a try. Personally, I
miss those cut to length plastic plugs that you could hammer into tight
holes. Ideal for twinthread screws but not sighted in the sheds for many a
long year. Anyone?