# Drill bits for concrete.



## Steliz (22 Apr 2020)

I want to attach my air filter unit to the ceiling of my workshop but I'm having some fixing issues.
The ceiling is concrete with a coat of render (I'm in the basement) and the unit weighs 29kg and has 4 screw in hooks near the corners. I bought a set of 4 hooks with a 40mm threaded section that came with their own plugs and, according to the packet, are rated for 60kg. The unit will be over the door which means that I will walk under it numerous times a day and I would prefer that it didn't kill me while protecting my lungs!
My issue is with drilling the holes. I have a fairly cheap corded drill (750w) and masonry bits but I can't get through the concrete to a depth of 50mm. I know the bits can't be very good quality as I've rounded over 3 so far! What would be a better choice of bit or should I consider a different approach?


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## Trevanion (22 Apr 2020)

Are you drilling into steel reinforcement?


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## Phil Pascoe (22 Apr 2020)

You got there before me.


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## sunnybob (22 Apr 2020)

Steel reinforcement rods are spaced out through the concrete. You know if you hit one, the drill goes slowly sideways.
But there are some really, really cheap and nasty chinesium masonry drills out there, which struggle getting through hard cheese.

Buy a known make drill bit (bosch,de walt, etc etc), and if you only get 2" in, move the hole a half inch in any direction. 
If the holes end up not in line with the holes in the unit, just use some metal plate and bolt the unit to the plates that are screwed to the ceiling.


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## Doug B (22 Apr 2020)

From the sounds of it you need an SDS drill & bit, if you are hitting a bit of aggregate in the concrete you’ll struggle to get through it with an ordinary masonry hammer drill & bit.


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## Steliz (22 Apr 2020)

Trevanion":2xgkefl7 said:


> Are you drilling into steel reinforcement?



That did cross my mind but I have tried 3 of the 4 holes and had a problem with them all and there are no sparks or evidence of rust anywhere. The first hole was a struggle for about 10/15mm through concrete then I hit a void and I had to go upstairs and check I hadn't gone through the living room floor! The next 2 I could get about 20mm in and that was it, progress stopped. I tried new bits but they got destroyed with no more progress.
I put some lighting up last year using fairly short screws and that was tough going too.


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## Distinterior (22 Apr 2020)

SDS drill.....Job done!


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## GarF (22 Apr 2020)

That or the Bosch multi-construction bits (the ones with the flutes painted blue) these have worked for me round our house where the bricks are about the hardest I've ever come across. Including with the hammer action turned off for the sake of accuracy. Amazing
G


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## Aquachiefofficer (22 Apr 2020)

A couple of years ago I bought a tungsten carbide tipped Proteco masonry bit to drill through 100mm concrete. I believe they're available as SDS and standard versions. I would recommend them.
Paul


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## RobinBHM (22 Apr 2020)

youve probably hit some flint aggregate

thats hard stuff

a Titan SDS would be your friend -or equivalent Chinese cheapie -if they are still in stock, I heard there was a bit of an issue with supply chains these days -I'm not sure what, there's been nothing on the news


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## Steliz (22 Apr 2020)

OK, thanks for the replies. I did buy an SDS hammer drill a little while ago but as I didn't expect to use it much I didn't want to spend too much so I bought one in Lidl. The chuck cracked in half at the first pull of the trigger!


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## HappyHacker (23 Apr 2020)

+ 1 for decent drill bits. On a job the customer was helping me by drilling some holes in a concrete panel using his decent battery hammer drill. He was getting nowhere. I loaned him one of my Bosch bits and straight in no problem. 

I agree with the posts saying there maybe problems with rebar, the fact that you get in the same distance on all holes indicates there is possibly something there.

An SDS is the answer as they generally make light work of most stuff, note I said generally.


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## owen (23 Apr 2020)

Either try an sds drill or first it's worth trying the blue bosch multi construction drill bits in a normal drill. They're loads better than cheap bits. Also worth starting with a small bit before the bigger one to make your life easier.


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## Racers (23 Apr 2020)

Get or hire a SDS its the only thing that will reliably work on concrete.

Pete


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## Phil Pascoe (23 Apr 2020)

I tried to put holes in walls when we moved. I couldn't find my SDS so I used a Ryobi that I bought cheaply in a charity auction specifically to fit my drill stand. Even on hammer with decent bits it wouldn't cope with blocks full of elvan - the bits were coming out pointed and red hot. I borrowed my bil's Bosch SDS and with decent bits I did the job with no difficulty whatsoever (I found my DeWalt SDS the following day).
Use decent kit. If you emptied my drill case the cost of drill bits, core bits etc. would add up to way more than the drill cost.


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## Deadeye (23 Apr 2020)

I had a similar problem drilling into the wall for my wood rack. I think the old stable wall has engineering bricks in it. I have a decent hammer drill (Milwaukee) and bought a good bit - but got nowhere.
I invested in a mid-price SDS and it's life changing!


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## Bm101 (23 Apr 2020)

Just for knowledge probably no help to the OP. (Sorry) DIY use but for the price this sds set is bang on. I've knocked them about a bit and not a dent. My house is either a sandstone extension or concrete render that kills normal cheaper bits. Like I say diy use. But I'm well happy with the performance. For the price and size variety it's unreal.
https://www.screwfix.com/p/sds-plus-sha ... eces/8849v

Re: the original op's issue. There is one other possible solution.... check the weight bondings. Seem ok tbh if braced while drying.
https://www.ct1.com/our-products/power-grab-n-bond/


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## Steliz (24 Apr 2020)

All sorted now, thanks for all the input. I bought a Bosch bit that had a 4 way (cross) tip and borrowed an SDS drill and it went through the concrete like a hot knife through butter. I turned the ceiling into Swiss cheese trying to find a place where I didn't hit any voids, there seemed to be a lot!



Bm101":3o9g4txz said:


> Re: the original op's issue. There is one other possible solution.... check the weight bondings. Seem ok tbh if braced while drying.
> https://www.ct1.com/our-products/power-grab-n-bond/



Ha! The concrete ceiling has a 10mm layer of render and an uncomfortable amount of voids so I'll give this a miss, thanks Bm101.


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## Bm101 (24 Apr 2020)

Steliz":3741geqr said:


> All sorted now, thanks for all the input. I bought a Bosch bit that had a 4 way (cross) tip and borrowed an SDS drill and it went through the concrete like a hot knife through butter. I turned the ceiling into Swiss cheese trying to find a place where I didn't hit any voids, there seemed to be a lot!
> 
> 
> 
> ...


Tools for the job. Good result in the end Steliz. Job done at any rate.


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## gregmcateer (25 Apr 2020)

Doug B":2jby7gou said:


> From the sounds of it you need an SDS drill & bit, if you are hitting a bit of aggregate in the concrete you’ll struggle to get through it with an ordinary masonry hammer drill & bit.


I agree. If your not going to need an sds drill again, see if a mate nearby has one. Or hire one if no local mate. 
If you're near Stourbridge, you're welcome to borrow mine
HTH


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## david.tamlaght (14 Sep 2022)

Anyone without an sds drill really needs to take the step and buy one .decent corded ones are available for 100 quid.no brainer .
if that doesn't work,your hitting steel id think.
thunderbolts are best for fixing and going into the centre void of the slab will not be an issue with them either


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## Phil Pascoe (14 Sep 2022)

Nearly two and a half years ago, I expect he's sorted it by now.


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## david.tamlaght (15 Sep 2022)

Phil Pascoe said:


> Nearly two and a half years ago, I expect he's sorted it by now.


oops,didn't take notice of that


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## Homeless Squirrel (16 Sep 2022)

Steliz said:


> All sorted now, thanks for all the input. I bought a Bosch bit that had a 4 way (cross) tip and borrowed an SDS drill and it went through the concrete like a hot knife through butter. I turned the ceiling into Swiss cheese trying to find a place where I didn't hit any voids, there seemed to be a lot!
> 
> 
> 
> Ha! The concrete ceiling has a 10mm layer of render and an uncomfortable amount of voids so I'll give this a miss, thanks Bm101.


Hi you can use inserts or likes of Rawl bolts with chemfix plus other way is put section of threaded rod in held with chemfix then place item up and do nuts up.
Plus can bond a sheet or piece of wood to concrete with chemfix/Gripfill then attach unit to that

ho well i noticed late but maybe useful for others?


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