Drills and drill bits

Alex

Well-known member
Hi guys,

My first time owning a drill so please be gentle with me, I have done quite a bit of bolting before but with someone else's drill. Now I finally have my own which is a Milwaukee Hammer drill. Now I purchased what I assumed would be the right bit which is a masonry bit but for some reason when I tried it out on my rockery (which happens to be limestone) but it seems to be taking forever to drill a hole. It normally takes it 30 seconds from experience, but I gave up after 2 minutes, after only making an inch of progress.

Now I really hope I have not purchased the wrong drill! Its two weeks before I leave for Armenia, is it the bit, do I need a more expensive one? Before anyone asks, yes it was spinning the right way and yes I had engaged hammer mode.

Any ideas???
 

Benfool

Member
SDS or non SDS?

If SDS these are the best bits you can buy:

https://www.hilti.co.uk/c/CLS_POWER_TOOL_INSERT_7126/CLS_CONCRETE_DRILL_BITS_7126/CLS_HAMMER_DRILL_BITS_7126/r4429

B
 

nobrotson

Active member
You want a drill bit that is designed for drilling into concrete or similar, which is sometimes different from a drill bit advertised as a masonry bit. Hilti make excellent ones that I have always used, as Ben says. Try and get one with 4 edges for max efficiency. Milwaukee are a reasonable brand but I have never known anyone to use one of their drills for bolting caves so maybe they don't hack it. I would have gone for makita, Hitachi or Bosch since I know their products work well bolting caves.
 

Leclused

Active member
First of all which drill did you buy? A M12 or a M18 (or an other one)

If I compare both drills with fe a Hilti tea-6 then the power of the two Milwaukee is less more

ME12:  350 in lbs ==> 0.46KJ
ME18: 1200 in lbs ==> 1.6 KJ

The Hilti gives 2.5KJ

I hope I did the conversion correct if so then the Milwaukee drills seems a little underpowered for the job

Concerning bits I (and our other clubmembers) mostly use Hilti drill bits. These are expensive but mostly the best and in case of early damage (broken head fe) you can mostly get a replacement in warranty; On the Hilti drill bits there is a marking (Red mark)  that indicates wear and if the marking is not gone and the bit is broken then Hilti will replace the bit in most of the cases we had.


 

andrewmcleod

Well-known member
https://www.ebay.co.uk/itm/Hilti-TE-CX-8-17-SDS-Plus-Drill-Bit-Quad-Head-8mm-x-170mm-Brand-New/223552424038

for 8mm throughbolts less than 100mm or so in length. Same as Ben recommended.
 

andrewmcleod

Well-known member
My baby Makita DHR165 puts out 1.3J and while it probably takes most of a minute to put in a long 8mm hole, I have made 14mm holes with it (albeit not super quick!) and I reckon it would do 16mm (supposed to do 16mm in concrete, although that is probably weaker than most limestone...)
 

Benfool

Member
Yep, unfortunately for bolting you really need an SDS drill - a combi drill just wont cut it (as you've seen). The bits I suggested wont fit either.

I suggest you try and send it back and buy a proper SDS drill instead.

B
 

Leclused

Active member
An complete overview about the M12 SDS drills

https://www.milwaukeetool.eu/m12-fuel-sub-compact-sds-plus-hammer/m12-ch-eu/

I would go for a set with a proper battery, so the 6.0Ah or the 4.0Ah.  The 2.0Ah will not get you enough when you need to do a lot of drilling.

For bolting this should to the trick. I'm not sure how the drill will work when drilling capping holes. Imho the 1.1J seems a bit underpowered for that.
 

Alex

Well-known member
Thanks for the help guys. Glad they have a 60 days return policy! I thought it being a hammer drill and pretty powerful it would do the job. It's not too late they reckon I can get the SDS one in a day or two. Thanks for the help guys.

(I only want it for bolting, not planning on using it for capping).
 

Alex

Well-known member
I had basically bought the wrong M18 (No internet and phone only does not make good drill purchasing).
 

TLH

Active member
Hi Alex,

Unsure if the attached will be viewable by anybody but it's a screenshot of what I use for both work and bolting.
You would have used mine out in Matienzo a few timei I think.

What you've got (by looks of the link) is a combi which, although will drill a hole in soft rock, will struggle with anything and just eat batteries.

Tom
 

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Chocolate fireguard

Active member
Leclused said:
First of all which drill did you buy? A M12 or a M18 (or an other one)

If I compare both drills with fe a Hilti tea-6 then the power of the two Milwaukee is less more

ME12:  350 in lbs ==> 0.46KJ
ME18: 1200 in lbs ==> 1.6 KJ

The Hilti gives 2.5KJ

I hope I did the conversion correct if so then the Milwaukee drills seems a little underpowered for the job

Concerning bits I (and our other clubmembers) mostly use Hilti drill bits. These are expensive but mostly the best and in case of early damage (broken head fe) you can mostly get a replacement in warranty; On the Hilti drill bits there is a marking (Red mark)  that indicates wear and if the marking is not gone and the bit is broken then Hilti will replace the bit in most of the cases we had.

I think the in lbs figures are the maximum torque the drills will generate (I guess under stall conditions).

Although the unit of in lbs can also be a unit of energy the conversion (to about 40J in the case of the ME12) gives energys that don't correspond to anything that makes sense so far as I can see.
The impact energy of a drill, sometimes quoted in the specification, is usually around the 6J mark for a drill that would be used underground.  I think one with an impact energy greater than about 10J would come with a mains cable attached.

From what I have been able to work out, the torque figure will be a guide to the maximum feasible bit size and the impact energy a guide to whether the rock will be broken up in large enough quantities.
Figures about 2J and 1000in lbs seem to be the minimum for a drill that will be any use underground.

 

andrewmcleod

Well-known member
Chocolate fireguard said:
Although the unit of in lbs can also be a unit of energy the conversion (to about 40J in the case of the ME12) gives energys that don't correspond to anything that makes sense so far as I can see.
The impact energy of a drill, sometimes quoted in the specification, is usually around the 6J mark for a drill that would be used underground.  I think one with an impact energy greater than about 10J would come with a mains cable attached.

From what I have been able to work out, the torque figure will be a guide to the maximum feasible bit size and the impact energy a guide to whether the rock will be broken up in large enough quantities.
Figures about 2J and 1000in lbs seem to be the minimum for a drill that will be any use underground.

I think an impact energy of 6J would be a _big_ drill. The biggest cordless 36V Makita I can see only has 2.5J of impact energy but will drill a 26mm hole in concrete. I can see there are cordless drills around 3J but they are likely to be massive (>3kg) and not expedition-friendly.

My little Makita is only 1.3J and is more than capable of drilling 8mm and usable up to at least 14mm. For expedition, the smaller drills are much more practical than the beefier monsters needed for putting in lots of 16mm holes for P-bolts. The once-popular Bosch Uneo only puts out 0.5J or 0.6J of impact energy (depending on the model) - although people certainly didn't buy them for the drilling capacity, they bought them because they weighed a little over 1kg!

Edit - Hilti's biggest(?) 36V drill comes in at 3.6J and 5.1kg.
 

Chocolate fireguard

Active member
andrewmc said:
Chocolate fireguard said:
Although the unit of in lbs can also be a unit of energy the conversion (to about 40J in the case of the ME12) gives energys that don't correspond to anything that makes sense so far as I can see.
The impact energy of a drill, sometimes quoted in the specification, is usually around the 6J mark for a drill that would be used underground.  I think one with an impact energy greater than about 10J would come with a mains cable attached.

From what I have been able to work out, the torque figure will be a guide to the maximum feasible bit size and the impact energy a guide to whether the rock will be broken up in large enough quantities.
Figures about 2J and 1000in lbs seem to be the minimum for a drill that will be any use underground.

I think an impact energy of 6J would be a _big_ drill. The biggest cordless 36V Makita I can see only has 2.5J of impact energy but will drill a 26mm hole in concrete. I can see there are cordless drills around 3J but they are likely to be massive (>3kg) and not expedition-friendly.

My little Makita is only 1.3J and is more than capable of drilling 8mm and usable up to at least 14mm. For expedition, the smaller drills are much more practical than the beefier monsters needed for putting in lots of 16mm holes for P-bolts. The once-popular Bosch Uneo only puts out 0.5J or 0.6J of impact energy (depending on the model) - although people certainly didn't buy them for the drilling capacity, they bought them because they weighed a little over 1kg!

Edit - Hilti's biggest(?) 36V drill comes in at 3.6J and 5.1kg.
Yes, I just checked a few specs.
I should have done that earlier instead of relying on my memory of what I looked up a while ago when I got interested in an earlier thread on drills.
 
On the Hilti drill bits there is a marking (Red mark)  that indicates wear and if the marking is not gone and the bit is broken then Hilti will replace the bit in most of the cases

On the Hilti bits I've got the wear mark is a grove 1 - 2 cm from the tip, not coloured. Hilti replaced one for me where the tip chipped. That was the Bristol UK store which is closing shortly.

I'd certainly recommend their bits.
 

Subpopulus Hibernia

Active member
Leclused said:
An complete overview about the M12 SDS drills

https://www.milwaukeetool.eu/m12-fuel-sub-compact-sds-plus-hammer/m12-ch-eu/

I would go for a set with a proper battery, so the 6.0Ah or the 4.0Ah.  The 2.0Ah will not get you enough when you need to do a lot of drilling.

For bolting this should to the trick. I'm not sure how the drill will work when drilling capping holes. Imho the 1.1J seems a bit underpowered for that.

I bought an Milwaukee M12 recently, mostly used it for capping thus far. Typically I can get about 9/10 8mm holes from a 6.0Ah battery, which is enough for the sort of light-duty capping I do.
 

Leclused

Active member
Subpopulus Hibernia said:
Leclused said:
An complete overview about the M12 SDS drills

https://www.milwaukeetool.eu/m12-fuel-sub-compact-sds-plus-hammer/m12-ch-eu/

I would go for a set with a proper battery, so the 6.0Ah or the 4.0Ah.  The 2.0Ah will not get you enough when you need to do a lot of drilling.

For bolting this should to the trick. I'm not sure how the drill will work when drilling capping holes. Imho the 1.1J seems a bit underpowered for that.

I bought an Milwaukee M12 recently, mostly used it for capping thus far. Typically I can get about 9/10 8mm holes from a 6.0Ah battery, which is enough for the sort of light-duty capping I do.

Not bad thus.

I drill 10mm  / 400mm .. 600mm holes for straws ;-) and therefore we use more powerfull drills (Hilti and Bosch).
For bolting we have 2 leightweight bosch drills mostly used during expeditions
 
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