Regular/Hammer drill when drilling in concrete

V8TOYTRUCK

Flashlight Enthusiast
Joined
Jul 31, 2001
Messages
1,793
Location
San Gabriel Valley + Burbank
I feel like a total idiot. I am posting in hopes that this will never happen to someone else and save you some time.

I purchsed a aluminum threshold for my door which required that I drill 3 1/4'' holes in concrete. I bought a kit that had concrete anchors and a masonry bit. On the back of the package it says a hammer drill is optional. So I figured I would just press down harder with my regular drill. So I put the bit on my regular drill and drilled 2'' in about 30-45mins. First I thought to myself ''What a crappy freakin drill bit.'' It started to get late and my neighbor came over wondering what I was doing. He noticed that I was using a regular drill for concrete, so he went to get his cordless hammer drill. I thought to myself, a cordless drill? How is this going to have enough power to drill through concrete!? I made 2 more holes in about 15 seconds almost effortlessly. /ubbthreads/images/graemlins/twakfl.gif

Turns out a hammer drill isn't just a heavy duty drill with an extra handle on it! It actually hammers and chips away while drilling. /ubbthreads/images/graemlins/ohgeez.gif

So whenever you have to do some drilling in concrete, remember to use a hammer drill. It will save you a lot of time. /ubbthreads/images/graemlins/whoopin.gif
 

jtr1962

Flashaholic
Joined
Nov 22, 2003
Messages
7,506
Location
Flushing, NY
Just out of curiosity did you use a regular bit or a masonry bit for the first hole? A decent masonry bit would have the hole drilled in a minute or two, even without a hammer drill, unless you encountered some large pieces of aggregate (i.e. stones) in the concrete. BTW, unless the bit is designed for it, a hammer drill will wear bits very fast.
 

turbodog

Flashaholic
Joined
Jun 23, 2003
Messages
6,425
Location
central time
Let me guess...... it went something like this.

1. Hey!, what's that sound?

2. HEY!, you're finished?
 

gadget_lover

Flashaholic
Joined
Oct 7, 2003
Messages
7,148
Location
Near Silicon Valley (too near)
It's amazing that hammer drills barely have any hammer at all. The bit only moves a fraction of an inch, but that's enough to break brittle things like stones that stop your normal drill.

Daniel
 

bjn70

Flashlight Enthusiast
Joined
Nov 25, 2004
Messages
1,097
Location
DFW, TX
I used an actual hammer for that one time.

When I noticed that my rotary drill stopped making forward progress I took the bit out of the drill, put it in the hole and used a hammer to break up the piece of aggregate that was stopping me, then went back to work with the electric drill.

Back in the old days they used to drill holes in rock that way. The drill bit was a rod with a cross formed in the front. They hammered on it, rotated it slightly and hammered some more. This powdered the rock and they would blow out the fragments.
 

PlayboyJoeShmoe

Flashaholic
Joined
Sep 4, 2002
Messages
11,041
Location
Shepherd, TX (where dat?)
We drill a LOT of 3/8" holes four at a shot.

We use a Bosch Corded Hammer Drill. Dad pushes down HARD... and doesn't always drill a deep enough hole.

The trick for busting thru rocks is light pressure and let the drill work.

Anyhow, I can't even imagine using a regular drill!!!
 

Sway

Flashlight Enthusiast
Joined
Aug 25, 2003
Messages
1,721
Location
North Carolina
Milwaukee Magnum 1/2 inch hammer drill, highly recommended eats through brick, concrete and rock like butter. A little over kill for around the house but it's like owning a mini jackhammer /ubbthreads/images/graemlins/thumbsup.gif

Later
Kelly
 

V8TOYTRUCK

Flashlight Enthusiast
Joined
Jul 31, 2001
Messages
1,793
Location
San Gabriel Valley + Burbank
I used a masonry bit for the first hole. I figured I hit a large rock or something in the concrete. Pushing down really hard on the drill didn't help it much either.

Turbo it went something like this,

Hole 1: @#$@!@ WTF!!! !@#W@#$@#!!! 2'' in 30 @#$@ MINUTES!!
Hole 2/3: OMG! You freakin moron. Head slap + doh!
 

chimo

Flashlight Enthusiast
Joined
Sep 16, 2004
Messages
1,905
Location
Ottawa, Canada
I have had very good success using a TAPCON bit with a regular drill. I used a bunch to secure my shed to a concrete base. You can get these at Home Depot.

Paul
 

modamag

Flashlight Enthusiast
Joined
Aug 16, 2004
Messages
2,101
Location
Bay Area, CA
Bosch Rotary Hammer Drill & Bosch SDS-plus® carbide bits are the ticket.

However, if you're drilling a ka-dozen of them like I did two weeks ago help building my inlaw's house, you're gonna need a small cold water bottle.

No.. not for me ... for the bit. After the 3rd or 4th hole the bit gets really hot, both my brother in-law broke or flatten those $8 carbide bit. I found that cooling them down and provide sufficient water during drilling significantly increased the life of the bit.

We had to bolt down 22 cross sectional members with 8 holes per member. That's 116+ holes and 4 different bits. /ubbthreads/images/graemlins/grin.gif

Thank goodness that we've past the sub-flooring, framing part. Now it's just the electrical (piece of cake!) and the decoration is left for the wives /ubbthreads/images/graemlins/wink.gif
 
Top