Rob" wrote in message
...
Any thoughts about the relative quality of SDS Drill Bits?

Living in a house built from 750mm solid stone walls and fitting a new
bathroom (an indoor one!) I've found myself needing to drill quite a lot
of holes. A 1000mm long 16mm bit from Screwfix lasts me about 3 holes
before going blunt. Actually not so much blunt, more that the tip has
just worn away. Cost per hole, about 6 quid! Are these 'cheap' drill
bits or will they all last like this. Just ordered a couple of Bosch
bits, to see if they're any better.

Also is there a correct way to drill? Should I be putting a lot of
weight behind the drill, or letting it do it's own thing. I think the
speed is constant on my GBH2-24 so I can't vary that even if I wanted
to.

Sorry if I'm stating the obvious, but you do withdraw the bit regularly to
let it cool don't you? I find when drilling old concrete posts etc (70+ yrs)
that the bit will get red hot on the tip and melt if it's not withdrawn
often. It's almost like the concrete melts in there too, no idea what's
actually going on though!

The biggest drill I have is 16mm x 450mm but this has been used for perhaps
100 maybe 200 holes in concrete or similar? Yes the end is a little worn
down, but it still drills fine. And yes it's a Screwfix bit, on a 2kg
Makita.

Alex


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