SDS drill 1-1/4"

[matt_i]

So I have 6 holes that I need to drill about 10" deep, 1-1/4" dia in concrete.

I have a Hilti TE-5 which is on the low end of the power scale although it has done a fantastic job thus far in 3/4" and under.

There is the possibility of buying a special 1-1/4" SDS-plus shanked drill bit for the job.

What I'm wondering is if its going to be a disaster or just slow going? A mainstream 1-1/4" carbide tipped concrete bit is going to be an SDS-MAX which is a different larger shank....

 

[Bretny]

Worth a shot. A bit is cheaper than a new drill and a new bit

 

[Jeffh40]

It will be slow, but should work fine.

A while ago I had to drill some 7/8" holes and all I had was an antique spline hammer drill. I would have killed to have a standard SDS drill with me that day. That took quite a long time to drill 4 holes, but it was eventually done.

 

[Kaizen]

If it’s for something not moved easily suchbas a lift I’d get the sds and not chance it. If using sleeve anchors drill all the way through the slab


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[rlitman]

They make SDS+ core bits that will put you back in the correct power range.

 

[strutaeng]

Looks like it might be a little too much. Capacity is up to 3/4", but recommended is only 3/8"?

https://www.hilti.com/media-canonic... Instruction TE 5-GE, TE 5-DRS GE (01) (EN-US)

We have a Bosch Bulldog here at work, and I know I've seen 1" bits covered with dust, so I know that set-up works. I'd say give it shot. I hope you are not in a hurry...

The core bits are also an option, but I think those are supposed to spin only, not hammer. We have a Huskvarna coring rig and it just spins.

Can't you borrow a Bulldog or similar? I've got a Bosch SDS Max 1 5/8" or something and it would drill that in no time.

 

[matt_i]

They make SDS+ core bits that will put you back in the correct power range.

I have seen them but discarded the idea thinking it would not be the correct tool for 10" deep? How do you deal with the slugs? Put in a pin (center shaft) and keep breaking them off?

I thought about trying to get a TE-25 (older model) to get more "hammer" on the SDS-plus but then it would probably sit around forever waiting for the next job. I suppose I could buy it and sell it at the end of the job....but I've tried that tactic before and haven't sold anything yet

 

[rlitman]

I have seen them but discarded the idea thinking it would not be the correct tool for 10" deep? How do you deal with the slugs? Put in a pin (center shaft) and keep breaking them off?

The SDS+ core will have a spring loaded pin for starting. Once you're in to the point that the core won't wander, you remove the center pin.

Then you just break and remove cores as you go. Horizontally, it's not that difficult. I used a 1-1/2" core to cut through 10" of poured foundation once, and it took maybe 5 minutes with my 1-1/8" rated Bosch SDS+.

Vertically, it might be more difficult to pull the broken cylinders out. I'd fish them with a piece of wire hanger.

 

[matt_i]

Ok good idea this is looking positive! Thanks!

 

[GRB]

No it isn't. Sorry.

Optimum is generally half of rated max capacity in concrete. So max is 3/4" means it is PERFECT for 3/8" in concrete.

Will take forever past 3/4". Unless your concrete is fresh and not high strength.

There aren't core bits that deep and not sure core bits even exist that small diameter. Core bits are expensive anyway.

Rent, borrow, or buy a SDS Max rated for the 1-1/4" to do the job poorly or above that to do it efficiently.

 

[drivesitfar]

Matt: i think that might be a bit much for your smallish rotohammer and sds or sds plus bit, but I suppose you could drill one hole and let us know.

I have both a milwaukee and delta rotohammer that use sds and sds plus bits and thinking 3/4 inch is about their max and probably not over a foot. if the hole is bigger and deeper i pull out my old Milwaukee 1.5 hammer drill that has a 1.5 & 1.25 and smaller bits and it's never failed so far.

the old Milwaukee 1.5 hammer drill uses the older SPLINE type bits.

good luck!!

 

[spike99250]

It will be fine, just keep pulling the bit out every so often.

 

[scottydosnntkno]

It will work just fine, but won’t be as fast.

I’m sure there’s some obscure test to determine optimum speed to determine the ratings.

It’s a factor of hitting force and rotational speed that determine how fast the hole is drilled. A Milwaukee 1-1/4 carbide bit end doesn’t care if the shank end is sds plus or sds max. It’s job is to hit and chip/grind the concrete away. Less hitting force (smaller drill) means less speed. It will still work, it’ll just take longer. It might take 5 mins per hole instead of 2 or 3.

As long as you don’t let the drill or bit overheat, it will work just fine. You have to decide is another half or hour of time for ten holes worth the rental cost. Many rental places when dealing with diamond items (bits or wheels) make you buy the entire bit cost anyways

 

[drivesitfar]

Matt: did you end up using your smaller drill or did you rent or borrow a bigger drill to drill that 1.25 inch hole?

 

[SGKent]

I wore out 6 carbide bits with a regular drill trying to make a couple holes for lag screws in the garage slab. Got maybe 3/8" deep before it would not go further. Bought a $79 SDS drill from HF on sale for like $59. Only took 5 or 6 seconds a hole to get to the depth I needed, and the bit still looked like new.

 

[scottydosnntkno]

I wore out 6 carbide bits with a regular drill trying to make a couple holes for lag screws in the garage slab. Got maybe 3/8" deep before it would not go further. Bought a $79 SDS drill from HF on sale for like $59. Only took 5 or 6 seconds a hole to get to the depth I needed, and the bit still looked like new.

Regular drills spin, they don’t hammer. So the bit overheated from spinning. ‘Hammer’ drills spin and hammer slightly so they work okay for up to say 1/4” holes for anchors.

Anything beyond that, you want sds, sds plus or max. They are more of a directional jackhammer. They drive the bit in 1/8 of a turn at a time with a large hammer force behind it. So it more chips the material away than grinds it away

 

[Stuart in MN]

Unless you expect to be doing this a lot more in the future, for only six holes I'd just go to my local rental store and rent the appropriate equipment.