In article ,
"Paul - xxx" writes:
andyv wrote:

I'm trying to hang a sliding glass door. It runs on a heavy metal bar
which is attached to the wall at 4 points. The kit provides 4 screw-in
fastenings which have an M8 threaded section which sticks out of the
wall and the bar bolts to.

I've used 12 mm sized plastic plugs as per the instructions but my
drill turned out to be slightly bent so my holes are sloppy and not
too accurate either. They are drilled either into a concrete lintel or
into concrete blocks.

How do I make this good? I'm thinking along the lines of Rawlbolts
which might be firmer, but how do I ensure that they are correctly
centred?

I think it'd be easier to fill these holes and drill good new holes ...

If you do that, start by drilling thinner holes than you need,
and then widen them with a larger bit. That often gives a more
accurately sized hole than trying to do it in one go, particularly
if you can get away without hammer mode for the second hole.

I always initially try without hammer mode, and only engage
hammer when it's needed. If you find youself going into a soft
brick or mortar, hammer mode can make a real mess of the hole.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]