What is a "Core" drill??

[Evil Gopher]

I was looking at some Hilti drills on E-bay...kept seeing "core" drills and drill bits....look huge....like a hole saw for concrete....but not realy sure..

so to clear up my lack of knowledge I figured Id ask.

What in the heck is a core drill? What is it used for/why???

thanks all.

[Pipestone Kid]

You are right, it is a hole saw for concrete. Used to drill through walls etc. for pipes conduit or whatever.
Jim

[PLUMBER RICK]

I was looking at some Hilti drills on E-bay...kept seeing "core" drills and drill bits....look huge....like a hole saw for concrete....but not realy sure..

so to clear up my lack of knowledge I figured Id ask.

What in the heck is a core drill? What is it used for/why???

thanks all.

a core drill is what joey hates me talking about:confused:

it's a diamond hole saw, typically water cooled and most commonly run in a coring rig/ stand. similar to a drill press, but get bolted to the concrete either on a wall or a floor and sometimes upside down on a ceiling:eek:

the drill is a heavy duty slow speed with clutch or shear pin. with water feed to cool the bit and wash away the slurry.

most common sizes are 1''- 12'' but they come bigger and smaller. the normal depth is approx. 14'' drilling without an extension.

typical applications are hole in concrete slabs, deck walls, curbs.
and yes they are expensive. they will drill right through rebar and electrical conduit:eek:

do i own 1:confused: no:eek:

i own 5 machines and 20+ bits:D

thursday i have a curb 4'' hole and monday i have a 3'' hole on a deck 12'' deep;)


rick.

[Aaron91]

1. Make sure your wearing all your PPE(Personal Protective Equipment) before using one.

2. Get ready for a work out.

3. Be prepared for the drill to kick, and hard.

[HVAC HAWK]

this is one type , you use water with this and it is nice to drill holes with
http://i154.photobucket.com/albums/s279/hawk63/TARDR150.jpg

[Evil Gopher]

WOW that was fast!!!!

Rick Do u do new construction???? I know we dont have one at our shop....but we only do service plumbing...and not much commerical buildings.....sooo is this something a plumbing company would normaly have around the shop???

[Frankiarmz]

The Hilti drills and core bits you are seeing on E-bay are simply hammerdrills with core bits that do in concrete what a hole saw does on a wood door. Instead of drilling a hole with what you know as a standard masonry bit, a core bit is more like a cup with carbide teeth around it's edge. The result is a smooth round chunk of concrete being removed. If you need a big hole you can achieve a silimar result using a smaller bit and chisel, it just won't look so pretty.

[biscuit]

My company does not own a core machine any more, but I do still have a lot of hole saws for one.

We just finished a dorm at a local university and had around 800 holes to sleeve for the project. Right off the bat, the concrete guys we screwing up and making a mess of things. We decided to take bids on core drilling to save everyone a lot of aggrivation.

We got all the holes drilled at a price per hole. The price was $13.00. Hell , I could not pass that up.

The same company will be doing some future projects with me. It just makes sense to do it at that rate.

Regards,

[PLUMBER RICK]

My company does not own a core machine any more, but I do still have a lot of hole saws for one.

We just finished a dorm at a local university and had around 800 holes to sleeve for the project. Right off the bat, the concrete guys we screwing up and making a mess of things. We decided to take bids on core drilling to save everyone a lot of aggrivation.

We got all the holes drilled at a price per hole. The price was $13.00. Hell , I could not pass that up.

The same company will be doing some future projects with me. It just makes sense to do it at that rate.

Regards,

$13.00 is dirt cheap. what size holes and how thick? was it a floor with a vacuum pad? it can be done cheap, but it needs to be mass production to make some money.

years ago we had a job that was robertson decking. to can the holes was a project. coring was clean and they even cored the metal decking. i don't recall the price per hole, but it was around what you paid 20 years later:eek:

spancrete was always cored. along with block walls.

now we have to be careful with all the post tension cables.

rick.

[jbergstrom]

Evil Gopher here's a few pics of a job I did this past summer which involved using a core drill to install a chain link fence on top of a retaining wall.


This is the Hilti unit I rented with a 4" diamond core being used...
2615

Shot showing base bolted down as Rick mentioned...
2612

This is what it looks like when finished drilling... (I went about 14" deep)
2613

I easy chipped out the core with my Hitachi jack hammer and a chisel bit...
2616

It will easily cut through rebar like Rick said...
2617

continued on next post...

[jbergstrom]

This is the rickety wooden fence I was hired to replace...
2618

The frame work is in and hanging the chain link fabric...
2619

All finished with privacy slats in place (very tedious job :speechless:)
2620

That fence will last a while, galvanized posts grouted in at 14" deep...
Couldn't have done it without the core drill :)

Thanks for looking :cool:

[Frankiarmz]

This is the rickety wooden fence I was hired to replace...
2618

The frame work is in and hanging the chain link fabric...
2619

All finished with privacy slats in place (very tedious job :speechless:)
2620

That fence will last a while, galvanized posts grouted in at 14" deep...
Couldn't have done it without the core drill :)

Thanks for looking :cool:

That's a top notch job you did, beautiful work. I know Hilti makes huge bits for their bigger drill but without the core bit you would never get through that rebar. Must have been an awful lot of work but it looks like it grew in place, well worth whatever you charged.

[biscuit]

$13.00 is dirt cheap. what size holes and how thick? was it a floor with a vacuum pad? it can be done cheap, but it needs to be mass production to make some money.

years ago we had a job that was robertson decking. to can the holes was a project. coring was clean and they even cored the metal decking. i don't recall the price per hole, but it was around what you paid 20 years later:eek:

spancrete was always cored. along with block walls.

now we have to be careful with all the post tension cables.

rick.

Yep, it was dirt cheap and we use them a lot.

The holes were anywhere from 2" up to 7" with most being in the 5" range. The thickness was around 4" on a corrugated metal floor decks.

Regards,

[drtyhands]

$13.00 is an unrealistic number for a 5" hole in our area.If I'm puting a price together for a job I make sure plug in $150 for the coring company.

[biscuit]

$13.00 is an unrealistic number for a 5" hole in our area.If I'm puting a price together for a job I make sure plug in $150 for the coring company.

$13.00 is a unrealistic number for a 5" core in any area in my opinion.

That number would be much higher if it were just a few holes, but we bring them on site and they will core several hundread holes for us using "south of the border" labor most of the time.

Regards,

[DuckButter]

Gopher,
There are two types of coring machines...the majority are anchored down.
Then there's the handheld, Hilti makes one.
The handheld is the best upper body workout I know when coring vertically, I used it extensively as an apprentice.
I used to request to do the coring with the handheld because it did wonders to my arms, shoulders and back muscles.
There are also dry bits that are designed for use without water/lubrication when in a finish area that water might harm.
Someone made a VERY important point...when drilling concrete slab, be sure there are no tension cables in the concrete.
Often the slab needs to be X-rayed to locate any potential obstacles.

[JimDon]

Go,
Never ever ever wear gloves when using a core drill. Way too many good men have lost an arm when using either a core drill or one of Milwaukee's Mag drills. They go to clear chips away from hole, glove gets snagged on chips or bit or spindle and they get pulled in. These drills will not stop for something like an arm. Take care.
Jim Don

[Jay6]

Here is a Milwaukee Core Drill. It's portable enough, notice the wheels for easy maneuvering. Definably different than your regular hammer drill.

http://www.ohiopowertool.com/item-detail.cfm?ID=4120-22

[Frankiarmz]

Here is a Milwaukee Core Drill. It's portable enough, notice the wheels for easy maneuvering. Definably different than your regular hammer drill.

http://www.ohiopowertool.com/item-detail.cfm?ID=4120-22

Very nice machine indeed. There are however large hammerdrill such as the Hilti TE 76 which I've used with dry core bits to drill very large and deep holes horizonatally. No water cooling or dust removal so it' a messy and very physical job.

[threecreeks3]

Perhaps I'm weird in this..I always really enjoyed running a core drill.All the setup layout etc was relaxing and enjoyable.I cored once for a month 6 days a week 10 hours a day most those holes were over 4'' and all the decks were about 12'' thick.I had a friend long ago that only cored or cut concrete he was never lacking for work but then he traveled about a 300 mile radius too.His van was a super setup everything in its place several of each bit or saw in a shelving unit on the non door side.He retired very comfortable,its a great biz for someone but not cheap to do the startup.
Sam