And in general is there a table or something that tells you what power of drill you need to drive various sizes of core bits?
Thanks.
Forgot to say it's not a diamond core bit it's the one with teeth.
With insufficient power you cannot cut as fast. It depends a lot what you are cutting. Almost anything will go through breeze block but high fired Victorian engineering brick is another matter entirely.
The guy who put the air vent in my outside wall had a lot of fun and burnt out one core drill. It became pretty well toothless. The bricks are old Victorian ones from local clay with small half roundish flints embedded in it that caused the drill to jam rotating the operator.
He got used to it after the first fairly spectacular jolt but the drill didn't and became toothless about half way through. ISTR it took him about three hours with one half hour break to get a new core drill.
Last time I did a 5 inch core I used the "next size up" SDS, that was through limestone and brick.
As Martin says, a lot depends on the material.
+1
I've done a couple of 100/115mm holes with a Dewalt 2kg SDS (700W, 2J impact) and found with one hole rotation was getting difficult which I put down to the waste material not being cleared from the cut groove and binding on the side of the cutter. The solution I found was to go in so far and then use a cold chisel and lump hammer to remove the core of material to the cut depth. This also allowed the wastes from the previous cut to be removed. I repeated this process a couple of times when going through 9 to 12 inches of material.
Its borderline, but will probably be ok - I have a 720W Makita 2kg class SDS, and have managed to drill a number of 4" diamond cores with it, and possibly a 5" (never tried 6"). However their 850W 8406 model is rated for 150mm cores.
There is more to it than just power.
The main thing with core bits, is there is a very high chance that you will snag and stall the core bit several times in drilling a core. That makes a safety clutch essential. The problem I found with using my SDS is that the clutch is set to let go at a much lower torque than is ideal for core drilling. So you have to take it very gently, and try and keep as straight as possible. (also hope the wall is not damp!) Otherwise it can be frustrating keeping the core actually spinning.
Core drills tend to be set at higher slip torques, and are usually equipped with long side handles to make it easier to keep a grip on it.
Also consider endurance, if coring hard stuff, then they can take a long time - so a drill rated for continuos operation is worthwhile - and not all tools are.
A 150mm bit is big for that, so you won't be cutting fast. It's got a clutch which is good. You may well shag the bit if you use hammer action, see any info that came with the bit if you have it. Always clear detritus from the cut, and frequently.
My old Powercraft SDS did a 115mm hole without a problem. Just take it easy; by being gentle I did a 38mm hole with an 18V combi (no hammer, of course). The force required was far less than the drill would take - beyond a certain point the rate reduced to near zero for some reason.
I cut a 2 or 2.5" hole in masonry with an ancient B&D once, it did it no problem. Your SDS is several times the power & several times less rpm, so I'd expect it to be capable. That doesn't imply it'll be quick. And there are wall materials out there that even an SDS drill can't penetrate.
Once you get the centre bit through & core drill a bit into both sides, it becomes possible to bust lumps out without breaking the face. You should break the centre plug out to at least reduce the risk of a jam, which is high and can injure you & the core drill. With a little care extra breaking out can speed things up some.
NT
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