Big masonry drill bits (not SDS)

[Barry Smith]

I need to drill a couple of holes (cavity wall) from the loft gable end to outside to pass cables through.

I decided it would be neater, easier and better to drill a 25mm hole, slightly angled so it doesn't "rain in" and fit a piece a pvc tubing (to prevent the cable chafing on the entry and exit) rather than drill a number of small holes (one for each cable).

I have a set of long masonry bits that go up to 12mm so a can start with those.

I thought it would be easy to find a long 25mm bit. It was. One such beast is a Rawlplug 32-350 at 35mm x 300mm but I can't find any website that specifies the shank diameter.

I could email/phone a supplier but I thought I'd just ask here on the off chance one of you has such a drill and can tell me.

TIA

Barry

[dom]

You need to move with the times and go to sds. I can't say I've seen large diameter plain-shanked masonry bits for years.

There are multi-material bits (I use in my combi drill), but only up to about 12mm

[newshound]

I wouldn't be surprised if a Chinese 1 metre 25 mm SDS bit and a basic drill for maybe £50 was cheaper than a "western" plain drill on its own

[dom]

I bought a screwfix 1m 25mm for =A325 when they were doing them cheap - fine in brickwork.

[Chris J Dixon]

The tool stall on the local market usually has a few very large drills at surprisingly low cost. I have so far resisted the urge to get one "just in case". The ones which are simply large have proved worth having.

Chris

[Barry Smith]

Plenty (non SDS) for less than £20 but they don't say what the shank diameter is.

's unlikely I'll need to drill more than a couple of holes so was trying to keep the cost to a minimum.

I appreciate SDS would be better/faster but the time it takes me to drill them isn't a big issue.

Barry

[John Rumm]

a chuck larger than 13mm.

You can also get core bits from about 25mm...

[Barry Smith]

Thanks. That's a good suggestion. I would imagine P&P on a 25mm x

300mm bit won't be cheap, so even if the cost locally is more, the total cost might not be more.

Barry

[Barry Smith]

That's the info I was looking for. Thanks.

But unless I'm very much mistaken, they won't drill through a cavity wall :-)

Barry

[Paul D.Smith]

...snip...

I hired an SDS and purchased an SDS bit from a local firm a few years ago. Wasn't too expensive and the difference in time and effort was well worth it. If you're drilling a core I believe you can hire those bits.

Paul DS

[Tim Lamb]

In message , " [e-mail]" writes

Umm... I did a series of 20mm Rawlbolt anchors in oldish concrete for our pergola and damaged quite a nice Bosch 2 speed drill. The *hammer* action will not now fully disengage and makes the drill useless for drilling in steel.

I suspect the hammer cam has slid along the shaft:-(

My 20mm TC tipped drills are all 12mm shank.

regards

[Geo]

I have the screwfix 12338 20mm (£5.89) but they also do a 25mm 11968 (£8.49). The shank on the 20mm is 1/2" (nearly 13mm).

Geo

[Andrew Gabriel]

CPC do a set of 3 (12,16,24mm) 1m long SDS bits which is often on special offer for about £8. I've used them quite often and they're still as good as new. Even if you don't want a long hole, they can be handy just for reaching a higher location without having to stand on something.

[John Rumm]

What gave you that idea?

I have drilled through a cavity wall many times with a core bit. If you go for a 6" long core then it is already engaged on the second leaf long before it has emerged from the first. Alternatively you drill a 8mm pilot right through and then drill the core from both sides.

[John Rumm]

Handy for drilling behind skirtings or architraves as well since they will flex enough to allow you to get a parallel hole even though the drill must be by necessity slightly offset.

[Barry Smith]

I thought the length of a core bit was approximately the same as its diameter. I will Google for longer core bits.

I'd prefer to drill fully from inside as the outside is approx 20ft off the ground. I'll be taking it gently so as to (try and) create a "clean" hole where it exits.

I've seen a 24mm x 1m SDS bit at a local (farmers) market for £5. I'm guessing it will be ok for a small number of holes. I know it's long, but drilling a 12mm pilot should guide it.

That being the case I'm now seriously considering buying a drill. My existing hammer drill, a Bosch CSB 450-2E must be 20 years old? and has never missed a beat.

I'm tempted by the Bosch GBH 2-23 DRE.

Barry

[Barry Smith]

See other post. I'm now considering buying a Bosch SDS drill. If it lasts as long as my current Bosch hammer drill it will probably outlive me!

Barry

[Barry Smith]

Thanks for the info.

Barry

[Barry Smith]

That's one website I never thought of looking on, which is a surprise as they are local to me (about 20 miles).

I think my wallet is geting worried :-)

Talking of standing on something... I saw a pair of stilts at work today. Not sure who was planning to use them but we do have people in at the moment fitting false ceilings.

Found a picture of the exact ones at