# Forum Home Renovation General Odds & Sods  how does a masonary drill bit get destroyed like this?

## wozzzzza

drilling some holes in concrete with my rotary hammer drill the other day, got to me third hole and got this awful smell then the drill stopped drilling properly, thought I had hit some reo but one closer inspection my drill bit had burnt out.
what causes this?? cheap drill bit? not doing anything out of the ordinary with it, not putting a lot of force on it, just drilling holes normally.

----------


## johnc

Most likely reo or something really hard in the aggregate which is less likely. That tip has got pretty hot to melt like that so it has spun for awhile after the tungsten broke free. It may have melted on the tungsten chips.

----------


## justonething

Did you cool the tip with water while you are drilling?

----------


## Bros

I've had that happen but I just got another drill and continued on.  
The purpose built hammer drills and the drills for these are from my observation from drilling nearly 100 holes are not affected by reinforcing mesh.

----------


## johnc

I've removed the Tungsten on Mesh, I'm assuming it just managed to grab in the wrong spot and Bob's your aunty, most times you will drill through.

----------


## lazydays

Any diamond they dug up with the concrete gravel mix????

----------


## wozzzzza

who knows, I aint pouring water all over my concrete floor to drill a hole to keep it cool, will make too much of a mess, I got another drill bit on the way, see how long that lasts for.

----------


## Uncle Bob

> who knows, I aint pouring water all over my concrete floor to drill a hole to keep it cool, will make too much of a mess, I got another drill bit on the way, see how long that lasts for.

  You just back it out every 30 secs or so and dip it in bowl/cup/whatever of water.

----------


## wozzzzza

I have been known to do that water trick but the bit never got hot enough to do it until it instantly self destroyed in half a second, the holes I drilled only took about 5-10  seconds each.

----------


## justonething

> You just back it out every 30 secs or so and dip it in bowl/cup/whatever of water.

  or a $2 spray bottle. 
Water is not only for cooling, but it facilitates removal of material, it keeps the drill sharp for longer, and you'll drill faster with less effort.  

> what causes this?? cheap drill bit?

  Now you know the answer.

----------


## China

Was it a low cost item, I have had trouble such as this in the past when using bargan basement drill bits, also I assume you are using a low speed

----------


## wozzzzza

yeah it was a cheapie an yeah low speed, not sure that drill has anything more than one low speed, ozito rotary hammer drill.
yes I know, cheap cheap cheap.

----------


## METRIX

> drilling some holes in concrete with my rotary hammer drill the other day, got to me third hole and got this awful smell then the drill stopped drilling properly, thought I had hit some reo but one closer inspection my drill bit had burnt out.
> what causes this?? cheap drill bit? not doing anything out of the ordinary with it, not putting a lot of force on it, just drilling holes normally.

  
You get what you pay for with tungsten bits these days. 
Try the new Kango bits available from Bunnings, they are German made, Had a brand new Sutton, burn out in one hole (40mpa concrete) got out the new Kango, went straight through, and kept drilling for the rest of the day, still looked like new. 
The also have quad SDS bits available, these are awesome, drill a nice clean hole, and fast.

----------


## Bros

> You get what you pay for with tungsten bits these days. 
> Try the new Kango bits available from Bunnings, they are German made, Had a brand new Sutton, burn out in one hole (40mpa concrete) got out the new Kango, went straight through, and kept drilling for the rest of the day, still looked like new. 
> The also have quad SDS bits available, these are awesome, drill a nice clean hole, and fast.

  Good  aren't they the only problem I had was sore hands after 10 holes due to the vibration

----------


## METRIX

> Good  aren't they the only problem I had was sore hands after 10 holes due to the vibration

  Didn't notice any vibration with them, but they do cut well. 
Have also been using the Kango Multi Purpose, these have sharpened Tungstens, and go through Brick, Steel, Timber, have been using them when doing deck, and the need for multi substrate drilling is required. 
They do a good job of both, but not as good as a propper HSS bit in timber, but cant beat being able to leave one bit in the drill when working on multiple substrates. 
Kango are bringing out some nice stuff and all made in Germany (about time we got some decent Non Chinese stuff here) and they are reasonably priced.

----------


## Bros

> Didn't notice any vibration with them, but they do cut well.

  I'm very delicate and the vibration through the handle of the drill gets at me even  though they cut well even reinforcing.

----------


## ringtail

Putting a ply floor down prior to secret nailing strip flooring. Used Irwin bits in my you beaut ozito :Biggrin: . Got over 200 holes per bit before they broke just below the sds section. The cutting tips were still perfect.  Quenching is not needed at all. Let the drill do the work, lift the bit out regularly to clear the hole and never push too hard.

----------


## Gaza

I normal buy Irwin sds bits or macsim bits don't have a problem   
Sent from my iPad using Tapatalk

----------


## METRIX

> I'm very delicate and the vibration through the handle of the drill gets at me even  though they cut well even reinforcing.

  You need to get a drill with AVT to protect those delicate hands.

----------


## ringtail

Or a tablespoon of cement  :Biggrin:

----------


## Bros

> You need to get a drill with AVT to protect those delicate hands.

  I'm talking about a real hammer drill.

----------


## phild01

> I'm talking about a real hammer drill.

  Very similar to my Makita rotary but without the AVT,  seems like a real rotary hammer drill to me and far better than my previous Ozitos etc.

----------


## Bros

> Very similar to my Makita rotary but without the AVT,  seems like a real rotary hammer drill to me and far better than my previous Ozitos etc.

  The one I was using was bigger than that.

----------


## phild01

> The one I was using was bigger than that.

  Yeah but sometimes size doesn't matter! :Biggrin:

----------


## Bros

> Yeah but sometimes size doesn't matter!

  Now where have I heard they before?

----------


## METRIX

> The one I was using was bigger than that.

  
Well that explains your problem, big tool poor quality bit, it's a combination for destruction.  :Biggrin:

----------


## METRIX

> Very similar to my Makita rotary but without the AVT,  seems like a real rotary hammer drill to me and far better than my previous Ozitos etc.

  This Makita is a nice drill, I have oneof them it has plenty of power for up to 16mm, is light and hasen't missed a beat.

----------


## Bros

> Well that explains your problem, big tool poor quality bit, it's a combination for destruction.

  Drilled over 100 holes in concrete and the tool was in perfect condition it was just the vibration that got to me after about 10 holes

----------


## Uncle Bob

> Drilled over 100 holes in concrete and the tool was in perfect condition it was just the vibration that got to me after about 10 holes

  [S]You need to try[/S] (no you really don't) Kangahammering a wall for an industrial range hood. Two ppl holding the machine up and one leaning on the end and trigger  :Wink:

----------


## wozzzzza

I bought a cheap no name "High Quality SDS Plus double flutes Cross-bit 4 cuts Masonry Hammer Drill Bit"
will arrive this week, will see how it goes.
don't drill many holes with it, the last cheap ass bit lasted 2 years.

----------


## woodchip

Bros you are using a rotary hammer set to the correct setting (rotary & hammer) & not just a big old hammer drill aren't you?.

----------


## jatt

Yep am pretty happy with the Irwins.   
Between us all in the shop drill a lot of holes into brick.  Dont use anything but SDS.
Using Metabo UHE28 and a cordless Makita rotary hammer, find on some bricks they hit a little hard.  For that there's a cheapie no name that hits softer in the arsenal.

----------


## phild01

> Yep am pretty happy with the Irwins.   
> ...find on some bricks they hit a little hard.  For that there's a cheapie no name that hits softer in the arsenal.

  I don't use a rotary on bricks, just the normal hammer drill for this so the brick doesn't smash apart.

----------

