Drilling into VERY HARD concrete

[securespark]

I dunno, Ive had to resort to an SDS for lintels, they are bl@@dy hard

Me too.

 

[robinbanks]

That drill bit looks blunt and knackered to me.

Er, it's a masonry bit. They don't cut the material like wood and steel bits do, they pound it into dust because they're a small chisel and the spirals evacuate it, so the tip doesn't need to be sharp like a wood/HSS bit

 

[aveatry]

Er, it's a masonry bit. They don't cut the material like wood and steel bits do, they pound it into dust because they're a small chisel and the spirals evacuate it, so the tip doesn't need to be sharp like a wood/HSS bit

Yes I know that but its still ****ing blunt

 

[Nige F]

Well you could do what I had to in the 70's as an apprentice - Rawlplug tool+ club hammer then a go with a " hammer drill " up a ladder with 240v. extension lead snaking up the ladder

 

[XrayDave]

So I now have 5 masonry drill bits - two DeWalt Extreme and 3 (minimum order quantity) Bosch CYL-9.

With 5 brand-new drill bits, I should be able to drill four-and-a-half holes in the lintel

"Drill-off" is tomorrow!

Dave

 

[noseall]

Well you could do what I had to in the 70's as an apprentice - Rawlplug tool+ club hammer

Star chisel/drill - ouch. Been there and done that.

 

[aveatry]

Come on then lets have your bets then
A bit that @robinbanks does not think is blunt
the Dewalt
or the Bosch CYL-9.
I am going with the Bosch CYL-9.

 

[johnny2007]

A second hand sds for £20 would've done the 4 holes in seconds without busting the bits.

 

[robinbanks]

Never pass up a reasonable excuse reason to buy more tools!

 

[johnny2007]

Never pass up a reasonable excuse reason to buy more tools!

Guilty!
However, many times I bought second hand tools that I needed to do 1 job and sold them on, sometimes at a profit if I could be bothered to refurbish them.

 

[opps]

Come on then lets have your bets then
A bit that @robinbanks does not think is blunt
the Dewalt
or the Bosch CYL-9.
I am going with the Bosch CYL-9.

I keep a set of the CLY-9 s in my rucksack. They are great for soft bricks but, to date, I have never encountered a reinforced concrete lintel that they would even dent.

I understand the OP not wanting to buy a SDS drill, but it looks like their only option. And as per my earlier post, I have broken the head off a regular SDS bit in the past when I hit a reinforcing bar. It was that experience that resulted in me doing some research and my buying the Makita Nemesis SDS bits. They enabled me to finish the hole and are still efficient.

 

[aveatry]

For a number of years now i have had the attitude that if i need a tool for 1 job i will buy the tool and I always end up needing it again sometime in the future. I have struggled in the past trying to do something with either inadequate or the wrong tool and the finished result suffered as a result and took longer to do and I ended up with some sort of injury.

 

[aveatry]

So what is the difference between an sds drill on rotation and hammer and a non sds drill set to hammer.

 

[XrayDave]

Okay so the results are in...

I had four and a half holes (6mm dia and 30mm deep) to drill.

Not impressed with either bit to be honest. If anything, the Bosch CYL-9 just edges it.

If it was a school report for the CYL-9 it would say: "After an impressive start to the term, they quickly went 'off the boil' and struggled to show their true potential."

For the DeWalt Extreme 2 it would say: "Disappointing on the whole and didn't really live up to expectations."

A brand-new CYL-9 made short work of the first hole - and I was impressed. It struggled to make an impression on the second hole. I switched to the DeWalt and started a third hole (in order to be fair). It struggled from the off - certainly not as good as the CYL-9 bit.

Swapping between these two bits (and quenching them in cold water after about 15-20 sec of hard hammer drilling), I managed to complete three holes fairly quickly in one lintel.

I went back to the half-hole in the first lintel and both bits really struggled to complete this hole.

I started drilling the last hole with the DeWalt bit and it initially seemed to make good progress, then I was swimming through treacle again - I have no idea what these concrete lintels are made out of, but boy oh boy is it REALLY HARD stuff!!

Both drill bits now look decidedly second-hand after onlt 4 and a half holes between them! The Bosch CYL-9 look somewhat better than the DeWalt which, despite only using it for 15-20 sec at a time and quenching, shows witness marks of heat stress. Surely somebody makes a drill bit that would work in this lintel?!

Both bits:

Bosch CYL-9

and

DeWalt Extreme

and

I hope this little (albeit non-scientific) comparison helps - and please don't bang on about how an SDS drill would have worked like a hot knife through butter - I'd love to have seen that but there was simply no point for just a few holes.

XRD

 

[freddiemercurystwin]

Could of hired one for not much more than you've spent on drill bits.