Bits- Drilling in concrete

[scratchedup]

Any idea how long a concrete bit should last. This is a 1/2" bit and after 5 holes the last one was very difficult.

The concrete is about 21 years old.

 

[rsanter]

I don't see anything wrong with that bit
I think you hit a very difficult rock in that concrete.
I have had that happen where I hit a rock that just about stops the bit.
I go,to the next hole and the but drills just fine again
Try drilling into the hole with a smaller bit, like half the size then go back to the size you want

Bob

 

[scratchedup]

I don't see anything wrong with that bit
I think you hit a very difficult rock in that concrete.
I have had that happen where I hit a rock that just about stops the bit.
I go,to the next hole and the but drills just fine again
Try drilling into the hole with a smaller bit, like half the size then go back to the size you want

Bob

Try drilling into the hole with a smaller bit, like half the size then go back to the size you want

Yes..I was lazy....this good idea.

BTW do you think it would cut better adding water to the cut?

 

[southalabama]

I wouldn't add water.

I would use a shop vac to keep dust out of the hole.

 

[A_Pmech]

Did you hit rebar?

 

[Monte]

get a SDS plus rotary hammer problem solved

 

[Brunel]

For drilling concrete, a rotary hammer is much better than an impact drill. I also find that the bits last a long time as they run at slower speeds and don't get that hot. But I agree that the bit in the picture looks OK.

My first rotary hammer was an old Bosch UBH2-20 which I bought cheaply at a car boot sale. I used it a lot and it still worked perfectly when I sold it 20 years later.

 

[Beemer533]

Nothing beats SDS for concrete drilling. Only time I don't use one is if I have only have a couple of small tapcons to put in... anything more and the SDS comes out..

 

[scratchedup]

Did you hit rebar?

Good question. I don't the cheap aXXsed builder used any.

+ it eventually went through.

 

[scratchedup]

This the hammer drill. Its been fantastic.

SDS bits I assume are much better.

The little bits gets beat up pretty bad. I drilled the hole about 3" down and would give the bit a break about every 60 seconds.

 

[Bigplum]

Just go SDS and never look back.

 

[dogdog]

if you are just doing few one off holes just get a garden sprayer those 2 gallon HDX ones from home depot or a spray bottle with cold water to cool your bit while drilling is fine. Spray lots of water to the bit and the hole you are drilling. SDS if you want smaller holes. personally I like sds Max with the sds max to sds adapter for extra $40 or so worked fine for me for years. and usually I Just used the regular drill if I am doing 1 off holes. still requires lots of water for drilling.

 

[dogdog]

that bit looks like a bosche brand from home depot.

 

[Sonorous]

that bit looks like a bosche brand from home depot.

Yes. Blue "Granite" is the branding I think. Good bits and not the OP's problem I don't imagine. I'm betting it was a nice chunk of aggregate or welded wire mats (whatever those are called??). Rebar, unless just in the edge, would probably have prevented - not just delayed - progress on the whole.
Been there!

At least you weren't drilling on a ceiling. That's where SDS rotary hammers are truly necessary!


Sent from my iPhone using Tapatalk

 

[dogdog]

That drill he have is fine with that good bit. just proper coolant, slower drill speed and pressure matters lot more in these smaller holes than anything else even with sds bits it is the same way. I usually burn a bit when I am too lazy to break out the water bottle and or fully pull the trigger and see how fast I drill the hole. I still needed water for coolant even with my sds max with those 4 cutter bits of any size if I am doing more than 1 hole. unless he is doing lots and lots of holes, then it is worth the investment for sdsmax drill. those bits ain't cheap either costed from $20 to $100 or more each.

Edit: looking at the blue tape on the bit the hole he is drilling is not more than 2" inches not likely to be a rebar.

 

[scratchedup]

that bit looks like a bosche brand from home depot.

yes
Excellent

 

[scratchedup]

Edit: looking at the blue tape on the bit the hole he is drilling is not more than 2" inches not likely to be a rebar.

how MacGYver-ish!

 

[djjsr]

Another big fan of the rotary hammer. I use one for anything 1/4" or larger. Even the cheap one from HF works great.

 

[scratchedup]

Game Changer.....

 

[Monte]

nice upgrade