Drilling Concrete

[wp6529]

(quoted from post at 06:27:48 09/05/23) While most people lump both types into one category....

If I was drilling 3/4 inch holes 5 inches deep in concrete I would be looking for a 'Rotary Hammer' and leave the Hammer Drill for mounting a hose real into brick mortar.

^^^ This

A hammer drill is great, use 95% for drilling and 5% for small masonry applications up to perhaps 1/2" dia.

A rotary hammer is a completely different mechanism that provides the impact separately from the rotation and is much more powerful. Indeed many rotary hammers have a hammer only mode you can use with chisel bits.

 

[Mule Meat]

Rotory hammer.

 

[Pete in Holland MI]

Borrowing or renting a good Hilti or Milwaukee hammer drill will yield good holes for you to anchor with. Forcing a carbide bit to drill a hole without the hammer action can result in a hole that goes off target and makes installation of a machine foot with multiple holes tough.

 

[Geo-TH,In]

I drilled 1.5 holes with my 20v 1/2 dewalt impact.
It took a little time.
The concrete blocks I drilled the holes in damaged the drill bit.
The 100 year old concrete blocks were more like steel instead of concrete.

 

[guido]

Bill Tattersall,

10 3/4 inches holes 5 inch deep? No brainer RENT A HILTY/rotary drill!



Guido.

 

[dlbuck]

We used Hiltys at work, dilled 3/4 inch holes all the time no problem, you just have too pull the bit out every so often too get the dust out of the hole. 10 3/4 inch holes won't take half an hour.

 

[Russ from MN]

I bought a nice hammer drill about 15 years ago from HF, it works great, will drill holes up to 1 inch with the bits that came with it, and I bought an extra set of long ones. It looks something like this one for $90. BAUER 10 Amp, 1-1/8 in. SDS Type Variable-Speed Rotary Hammer.

 

[glennster]

i am installing my lift this sunday. sds drive and 3:4 inch bit. my concrete is 12 inches thick for the lift with wire and rebar . i have the bit to go thru rebar

 

[teddy52food]

12 inched thick???????? Why? My shop floor is 4 inches with wire mesh built in 75 & no cracking. I did work on a road grader with wing & front snow plow on it for many years.

 

[glennster]

the shop floor was poured last year, 6 inch 6 bag mix with wire and rebar. the area where the lift is going is 12. inches thick. wire and rebar. the lift for sure is not going anywhere. mine is an 11k two post. i have seen failures with vehicles on lifts with insufficient base.

 

[glennster]

also 4 inches of concrete is too thin to install a 2 post lift.

 

[teddy52food]

It was OK for me. I have a 2 post .

 

[jimg.allentown]

I had to drill through a 12-inch foundation wall to install central A/C in my previous house. I looked into a rental, and found that I could buy an SDS drill from Harbor Freight for about HALF of what the rental would have cost me - complete with the bits I needed. I have had that drill for over 10 years, and have used it a couple of times since, and it still works well.