Blimey, these Rawlplug concrete screws...

[Andy Burns]

The cheaper ones only have rotary-hammer mode, more expensive ones allow roto-stop and non-hammer modes too.

[Bert Coules]

Ah, that makes sense, thanks. Is roto-stop hammer-action but no rotation? I can see that would be useful: like having a powered masonry chisel.

Bert

[sm_jamieson]

All the ones I've used do that (when in hammer mode). I assumed the piston thing is pistonning away all the time, but its only when you apply pressure that the end of the drill bit is moved close enough to the piston to get hit. Simon.

[Bert Coules]

Simon,

Yes, that makes good sense. Thanks.

Bert

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember robgraham saying something like:

If you read the Rawlplug page... "SUITABLE FOR USE IN: Pre-drilled o 6mm: concrete, full and hollow brick, clinker brick, stone, structural clay tile. Without pre-drilling: aerated concrete, timber. "

[The Medway Handyman]

Wot he said :-)

[Steve Walker]

That's it exactly.

SteveW

[Steve Firth]

Not just a masonry chisel, you can get SDS wood chisels.

If choosing a drill with rotostop, it's essential to check how it works on that particular drill. Some cheap ones stop the rotation but do not lock the chuck. This means that the chisel will twist around as you work. Not a problem with a point but a problem with flat chisels.

[Bert Coules]

Thanks for that, Steve.

Bert

[Bert Coules]

I've used these now (the Multi-Monti hex head version from Screwfix) and I'm pleased with the result. The only drawback was that I had to use a small socket-and-ratchet tool to get them in, and the final few turns took a good bit of effort. In fact I had to withdraw my first attempt, which froze absolutely solid with about half an inch still to go. I decided that perhaps I hadn't drilled deeply enough so I lengthened the hole and also used a blower to remove the dust and residue: the bolt then went fully home.

So thanks to everyone for this thread.

Bert

[Steve Firth]

fully home.

Damn, should have warned you about that. Cleaning the hole is essential.

[Bert Coules]

I should have known. I DID know, I just forgot in the sheer wild excitement of the moment. More thrills came when the plastic tube came adrift from my air canister and dropped irretrievably into the hole. I thought for a moment it might be a problem, but no: I suppose the bolt must either have crushed or demolished it...

Thanks to you and everyone else for the comments and advice.

Bert

[<me9]

I've found that if you don't remove the debris completely from the hole they seem to bottom. If you then re-drill, the hole seems about half an inch shorter than you originally drilled it. Re-drilling to the original depth and clearing out as much as possible got the screws fully home without too much torque.

[Bert Coules]

Yes, that was exactly my experience. Considering that the threads must actually be cutting into the concrete I was surprised, in the end, by how comparatively easy it was to get the bolts home.

It would have been even easier though with a socket I could have used in a drill/driver. Does such a thing exist? I asked in Screwfix when I bought the bolts but they had nothing.

Bert

[Andy Burns]

You can get socket bits in 3/8" hex fitting

[Bert Coules]

Yes, sorry, I put that badly: Screwfix had nothing *in the size I needed*. The bolts were 10x140mm and the heads a bit chunkier than 3/8". I was expecting that they'd have a set with different size sockets, but no.

Still, my socket-and-ratchet tool did the job.

Bert

[Steve Firth]

I have 1/4" 3/8" and 1/2" square drive adapters for use with my drill. I can't recall where I got them from - not from Screwfix. There are 1/2" and 1/4" versions available on eBay, worth considering if you intend to do a lot of this work.

sockets sets come with the adapters in the case - Halfords Pro range used to, for example. I have a case of their 1/4" drive sockets that came with a 1/4" hex to 1/4" square drive adapter.

[The Medway Handyman]

You can get adaptors that fit either the hex/chuck on a drill driver or impact driver - or the SDS drill. The other end then fits a standard socket.

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Bert Coules" saying something like:

I was sceptical at first, but am now convinced and will be using them a lot more. They're just so easy, make a fiddly job into a simple process and are much better than hammer-in fixers for the type of stuff I use them for.

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Bert Coules" saying something like:

That's exactly what I use on hex-head screws (the concrete fixers had Torx heads, so it was easy enough to simply put a Torx driver in the drill). For hex-head I have a small kit with a 1/4" drive set of sockets, but the key piece is a hex shank to 1/4" drive tool, which allows mounting of the sockets onto a power drill. I picked that up from Aldi a couple of years ago and it's been dead handy for exactly this sort of thing.