Re- fixing shelves - what size screws / drill bit?

[sobeitjedi]

Hi.

I bought 3 of these hidden bracket shelves from B&Q ..

http://www.diy.com/diy/jsp/bq/nav/n...refview=search&ts=1187387688258&isSearch=true

But had a bit of a problem fixing them ... the screws where reasonably think so I used the largest drill bit I had but the holes I made were too wide. So I filled with a strong poly filler glue and inserted the plugs. I waited for it to dry , put the screws in and put up the shelves. However, the shelves are too loose and are now on a slant! D'oh!

I want to re-attach them. Therefore, does anyone know what size drill bit, screws and plugs I need for a perfect and tight fit?

 

[big-all]

realy cant tell because i havent seen the brackets
assuming its a brick or other hard wall
but i suspect the larger brown plugs no7 masonery bit 60mm hole no10s by 2" or 5x50mm

if its stud or plasterboard you have a lot more work