Hammer drill blows per minute (BPM)

Reply

  #1  
Old 12-21-15, 07:14 AM
U
Member
Thread Starter
Join Date: Aug 2013
Posts: 68
Received 0 Votes on 0 Posts
Hammer drill blows per minute (BPM)

I am wanting a power tool that will act as a mini jack hammer essentially. I am going to be doing a number of jobs where I will want to break up concrete, mainly in my basement floor. So I am looking at 2 different hammer drills with different specs but are both 3 in 1 having a hammer/drill, drill and hammer only functions (see photos). One is a more traditional hammer drill (first photo) and the other (second photo) is a more heavy duty, SDS rotary one (but both are SDS). The traditional one is lighter in weight and seems to look more like a corded electric typical hammer drill with a chipping function but has a higher BPM rating of up to 5100 whereas the heavier one has a rating of up to 3900 (and a slower rotational speed). The lighter one draws 7.3 amps and the heavier one 10 amps.

Which one will be better for bigger concrete breakup jobs? I'm confused because the smaller/lighter one has a higher BPM than the bigger one. Does higher BPM necessarily mean more power for breaking up concrete, or does the size and weight of the tool matter more, even with less BPM? Can't decide. There is a $20 difference between the 2, with the bigger one being $20 more. They are on sale at Harbor Freight and normally the bigger one is $300 while the smaller one is $200.
Name:  image_24251.jpg
Views: 3795
Size:  18.2 KBName:  image_21842.jpg
Views: 3552
Size:  18.0 KB
 
  #2  
Old 12-21-15, 07:21 AM
G
Member
Join Date: Nov 2007
Location: MI
Posts: 2,634
Received 1 Vote on 1 Post
The hammer function on those only assists the bit in penetrating cement and aggregate--it doesn't break up anything. You would have to drill countless holes side-by-side and still have to break it away with a sledge.

You need a thick chisel to crack concrete so a true jack hammer is the right tool for the job. Unless your projects are very small you should be considering a rental.
 
  #3  
Old 12-21-15, 07:28 AM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 26,575
Received 790 Votes on 727 Posts
The rotary hammer, which has less but more powerful beats per minute is the one you want for "heavier" jobs. It is not a jackhammer, however, so don't expect it to work like one.

And I would never pay that much money for a Chicago electric tool. Northern tool has a rotary hammer for 149. Also a low quality tool that you will throw in the trash if anything goes wrong with it.
 
  #4  
Old 12-21-15, 07:34 AM
J
Member
Join Date: Jan 2011
Location: USA
Posts: 4,857
Received 83 Votes on 78 Posts
Anything that holds a round shank bit will be useless for busting up concrete.
Even my Bosch SDS bull dog would be to light duty and take to long.
I agree 100% renting a real electric jack hammer will make the job go a whole lot faster, the bigger the better.
Going to need a 20 amp. circuit and at least a 12-2 ext. cord.
Home Depot rents them.
 
  #5  
Old 12-21-15, 07:39 AM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,965
Received 6 Votes on 6 Posts
I agree with all the comments so far. Hammer drills have a light duty purpose, but an SDS drill acts as a hammer drill and a light jack hammer all in one. It is great for taking up linoleum, tile and other stubborn things. Use the right setting and right bit/blade and you're good.
 
  #6  
Old 12-21-15, 08:07 AM
U
Member
Thread Starter
Join Date: Aug 2013
Posts: 68
Received 0 Votes on 0 Posts
Maybe jack hammer was the wrong comparison to use as I am only needing it for lighter duty stuff around the house and not going to be breaking anything up more than 4" thick. At only $70 and $90 respectively on sale at HF it seems good and makes it worthwhile over renting when you're only spending a bit more to own the tool, especially when I need it for multiple jobs where separate renting jobs will just add up. The online reviews only seem to say good things about it too... nothing about having to drill multiple holes to break up concrete.
 
  #7  
Old 12-22-15, 07:55 AM
G
Member
Join Date: Nov 2007
Location: MI
Posts: 2,634
Received 1 Vote on 1 Post
Originally Posted by umjorge3
The online reviews only seem to say good things about it too... nothing about having to drill multiple holes to break up concrete.
If you sort the reviews to show the lowest ratings first you'll find plenty from people who tried to use this drill to break up concrete.
 
  #8  
Old 12-22-15, 08:00 AM
U
Member
Thread Starter
Join Date: Aug 2013
Posts: 68
Received 0 Votes on 0 Posts
I get it its not meant to be used as a full jackhammer which I said I wasn't trying to breakup a road way, and to me the positive reviews seem to outweigh the negative. Its all about the cost benefit ratio.
 
  #9  
Old 12-24-15, 09:58 PM
N
Member
Join Date: Aug 2013
Location: usa
Posts: 5
Received 0 Votes on 0 Posts
I own one of the heaver Harbor Freight SDS drills you're looking at. I bought it about 5 years ago as a one time use and throw it away tool. Five years later I still use it 4 or 5 times a year to cut holes in concrete floors or block walls. I drill holes around the perimeter and use the chisel to cut between the holes. I've used it on 4in and 6in concrete floors to put in sump pumps and it hasn't died yet. For the $89 I paid for it I couldn't have rented for less. I did however spend the money for good name brand drill bits.
 
  #10  
Old 12-25-15, 07:55 AM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: United States
Posts: 13,802
Received 252 Votes on 220 Posts
I also have a HFT SDS hammer drill similar to the one you posted. I have used it to brake up some small outside concrete stuff, but not for concrete slab demo. I have been satisfied with it.

ANY hammer drill I would not recommend anything other an SDS, SDS max, or spline drive hammer drill. Screamer hammer drills are only good for minor work IMO
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description: