How deep will this diamond core bit go ?

[andysideas]

I've never used a diamond core before.

I will be making a hole for a washing machine waste pipe.

I need to get through the wall, I see that some of the options on hte market have 'extensions'. Does this mean they can drill deep or just give a better reach ?

I've been thinking its better value buying a kit, and toolstation has a kit for =A3134

[meow2222]

theyre a closed cylinder, which limits drilling depth. Once youve drilled so far, knock the centre brickwork out with a chisel and drill again. Keep going till you hit the earth's core.

NT

[Ed Sirett]

Nope, the drill will foul the front face of the wall. You might be able to get a little further by remove the second handle off the drill. However core drilling even wall thickness holes tends to cause the drill to snag in the hole. On the better drills the high torque limit clutch makes a loud noise, on cheaper models something else gives and with only one handle that could easily be you.

You can probably get through a nominal 9" wall without an extension - just.

Extensions can be improvised by using a length of 1/2" iron pipe and a barrel coupler. Most dry diamond cores are threaded 1/2" BSP.

[weekendwarrior]

there is more on core cutters here-'core cutters

might need an extension arbor though

-- weekendwarrior

[John Rumm]

Simple enough in concept. You need a powerful drill (750W minimum), and it *must* have a safety clutch, because you *will* snag the bit at least once no matter how carful you are!

(I cut a 107mm core though a cavity wall today and snagged the bit at least three times while being very careful! Also for this sized bit my

780W Makita is a little underpowered - I hit the torque limit on it a number of times as well even when not snagging it).

Just better reach really. The depth of core you can drill in a single action is limited to the depth of the actual core bit cylinder. To cut deeper you need to withdraw the bit and break out some of the core drilled so far (a pointy chisel bit on the end of the SDS does it nicely).

With a 6 to 8 inch deep core bit and the typical 8" length arbour on the bigger diamond core bits you will have no difficulty with "normal" walls up to 12" thick.

You can also extend the range by drilling from both sides. Stick a hole right through the wall with a long 10mm plain masonry bit so that you can use it to align the core centre drill.

What order code 85987? Looks ok - the cores are a reasonable length although not as long as some (like as shown on order code 11683)

If you only need one hole, have you thought about hiring the bit? (and drill)

[andysideas]

Thanks John and Ed.

you say I do not use a drill with a torque limiter. I will check my drill, but I don't think it has. It's one of those big SDS drills the size of a fridge. Very powerful, but no torque settings. I only plan on drilling 35mm holes, so will just be careful not to 'break my arm' through snags.

I also know not to use hammer settings.

But to be honest, that website is exactly and I mean exactly what I wanted. The only thing that could better that would be a video !

[John Rumm]

If in doubt, go for a plain (i.e. not SDS) shanked arbour, and put a chuck adaptor into the SDS. That will at least introduce a capacity for "slippage" into the equation. The splined shank of a SDS arbour will not let go under any circumstance, a chuck will.

You can use it briefly to drive the pilot drill into the wall before the main cutter reaches the surface. Personally I like to pilot drill first anyway.

[meow2222]

Ah... time for change of mode. It depends on the size of the core drill. If its big enough that the drill fits in the hole, you can keep going.

If its even bigger, you can climb into the hole and keep going. And yes, we can assume that a longer extension lead will be needed, and that it will need clipping to the side of the hole as you go along to avoid breaking under its own weight. etc

NT

[Steve Walker]

Good points - never neglect safety when drilling to the earth's core

[andysideas]

Thanks that's all very helpful guys.

Not sure about this chuck thing you were trying to explain further above. If I'm having a blond moment (hold on where's the girlfriend) let me know. But any links to products with pictures always work well.