Why are core drills so expensive?

[John Aspinall]

I've been looking at core drills, for a possible project installing a handrail on some granite steps. A core drill, if you aren't familiar, looks like a portable drill press. A motor, looking like a heavy duty hand-held drill, is attached to a rack and pinion slider, enabling the drill to move perpendicular to the surface it's drilling, in a nice steady fashion. Equipped with a water-cooled diamond "coring" bit, this gives you a nice neat hole in stone; much cleaner than you could get with a hammer drill. (Google "core drill", for many pictures.)

So why are they so expensive? Compared to a hammer drill (rotary hammer,...) they seem to come in at 2-3 times the price. Is there so little demand for them?
(And why do so few rental outfits carry them? Which may, I realize, be the same question.)

[Ole Anderson]

Uh, the cost of diamonds?

Most rental places rent the core bits along with the machine. I believe they have some way of measuring how much of the diamond surface you used and charge accordingly.

I have seen cores as big as 18" in diameter in concrete 18" thick.

[John Aspinall]

Uh, the cost of diamonds?

To be clear, I'm talking about the cost of the drill, not the bits.

But you're quite right that the bits are costly too. Get the bit too hot, and you can leave the diamonds in the hole.

[Mike Wilkins]

These look like specialized tools, only used by the trade. I used to see the maintenance dept. at an old job use one when repairing a large machine. These babies have magnetic bases to stick to a metal surface, are both heavy and heavy duty. Not the sort of thing you would find in a contractor or woodworker toolchest. A rental place would be your best bet.

[Rich Engelhardt]

This is sort of weird...

http://www.walmart.com/ip/MK-Diamond...00000003260430

I searched for a core drill and a link came up for WalMart.
Does WalMart have some tie to Toolking?

[Jerome Stanek]

I have a couple Roto hammers One is the Black and decker macho and a milwaukee usa1 both are heavy duty drills that will handle diamond core bits

[Phil Thien]

I agree w/ poster above that it is limit market share.

I wonder if you could get one of those drill presses things that basically holds a hand-held drill.

[Jeff Nicol]

When I was working in the trades as a HVAC fabricator/installer we would use them for many different operations from installing railings, safety posts near doors to protect them from forklift traffic etc. We also used them to drill holes through walls, floors etc to allow pass through of ducwork, wiring, refridgeration lines and what ever was needed to complete the job. They were used on remodel jobs or if something needed to be changed after the concrete was poured as when it was a new construction job most all the holes where put in place ahead of time by either using sleeves or wood frame work for square openings.

Wtih that being said, these tools were owned by the company or at times if there were a lot of coring to be done we would hire a company that does the service for you as they had all the large core bits that would not be cost effective for us to have on hand for a 1 or 2 time need. These drills are ussually pretty heavy depending on the hole size the motor and gear reduction would be beefier to handle a 14"-18" hole through 12" of concrete! So to own one you would either have the need to core a lot of holes or just some extra cash laying around to buy all the tools to do any and all jobs. So I would either rent one or if it a fairly large number of holes, finding a coring service to come do the job for a fee would work.

Good luck,

Jeff

[Harry Hagan]

Some people use specialized tools on a regular basis. They need it. They also want it to be dependable—which means they’ll pay even more money. Manufactures know this.

People who don’t really need one, rent.

[Brian Elfert]

I wonder if you could get one of those drill presses things that basically holds a hand-held drill.

You typical hand held drill has does not have the power and torque of a core drill.

[ray hampton]

You typical hand held drill has does not have the power and torque of a core drill.

are your average core drill hand-held or bolted to a crane or back-hoe

[Ole Anderson]

I have seen core drills with magnetic holders with a rack like a drill press which are typically used by ironworkers to drill larger holes in steel and I have seen drills where the rack is held to smooth concrete with a vacuum and than there are the larger drills where you drill a few smaller holes and bolt the rig to the concrete adjacent to the hole you are coring. The bits for concrete are like a hole saw except with diamonds in place of teeth. Here is a pic of a vacuum base core drill (about $2500 new):

[Phil Thien]

You typical hand held drill has does not have the power and torque of a core drill.

Good point, the gearing is different, isn't it?

[Jerome Stanek]

My roto hammers turn slow and will twist your arm pretty good if your not careful

[Ole Anderson]

When is the last time you saw a 15 amp hand held drill? Turning 300 rpm.