Bosch recently introduced its most powerful rotary hammer in the Bosch RH1255VC 2-inch SDS-Max rotary hammer. It has innovative features designed to suppress the vibration that comes with drilling or chipping concrete. This is heavy-duty work, and it’s easy to see that a rotary hammer can be an ornery tool in its user’s hands. I was anxious to get the RH1255VC on some jobsites to see how it performed.
I’ve been a mason for 30 years, and I think I’ve done it all – laid block, stone, paver driveways, built fireplaces, waterfalls, outdoor kitchens with stonework, and other artistic projects. You may have read my Makita MM4 4-Stroke Power Cutter review where, among other stonework, we made large concrete radius tie beams on a new home. But no matter how technical the job, very often I have to do some demolition or clearing work of some kind. That’s where a tool like this Bosch rotary hammer comes in.
The first thing that struck me is the heavy-duty look of the Bosch RH1255VC. It’s certainly beefier than a chipping hammer you might pick up at a big box home improvement store, but it looks like the alpha male even among larger rotary hammers. That could be good or bad – this kind of tool needs the heft to get the jobs done, but it can’t be so heavy that it’s exhausting. I took the Bosch RH1255VC to a paver driveway job where I had to remove an 8-inch thick stoop (in fact, I used the power cutter reviewed in the link above for that job as well). I also used it on another jobsite where I drilled for rebar installation.
Good Vibrations
If you’ve used a rotary hammer for more than five minutes, you know the weight and vibration of the tool can quickly result in fatigue. Bosch addressed this by bringing the RH1255VC in under 27 pounds and using a clever decoupled main handle with a tuned mass damper integrated into the aluminum cover. Generally, when new tools are introduced, I like them to be lighter because lighter often makes the job easier.
A good balance has been struck with the Bosch RH1255VC because, as I mentioned above, to do the heavy duty work this tool is intended for, it needs to have some mass. It just can’t cause the user too much fatigue. Ultimately, the vibration control of this Bosch SDS-Max rotary hammer is very impressive. I felt very little vibration, and it made the job much more comfortable than other rotary hammers I’ve used.
A danger of rotary hammers is snags – that is, the bit gets snagged on rebar – and it can injure wrists, arms, and shoulders. Bosch Active Response technology is the clutch system that is designed to prevent violent wrenching when jams or snags occur. But be warned: the torque on this tool is so powerful that improper use can still result in violent wrenching. I even managed to bend a bit – when it’s in your hands, you know you’ve harnessed some power in the Bosch RH1255VC 2-inch SDS-Max rotary hammer.
Power On
The 15 amp motor has an absolute speed dial with six positions and provides up to 14.1 foot-pounds of impact energy which, coupled with the weight, is an impressive power-to-weight ratio. In practice, however, I don’t change the speed very often. I use one speed for chipping and one for drilling. It’s a nice feature to have, I suppose, but you will likely find one or two speeds that you use the majority of the time.
One of my favorite features of this tool is the fatigue-reducing auto lock-on, which eliminates the need to actively keep the trigger depressed. Bosch’s T Vario-Lock positioning also lets you rotate and lock the chisel to get the exact bite you need.
Another notable feature is the service display near the dial that alerts you when the carbon brush needs replacement. Last, but certainly not least, of the features is the SDS-Max bit system which provides tool-free bit changes and allows for larger bit use.
Performance
So there are a lot of features in play to make the Bosch RH1255VC more comfortable, convenient, and safe to use, but that amounts to nothing if it can’t get the job done. As I mentioned, the rotary hammer delivers 14.1 foot pounds of impact energy with its 15 amp motor. When it comes to chipping, there’s not much that will stand up to that kind of power. It’s only a matter of how small you want the pieces. There’s no doubt it gets the Pro nod there.
For drilling applications, 5/8 inch and 3/4 inch are my most common bits. Bosch provided each of those sizes for me from their Speed X line. If you’re not terribly familiar with Bosch accessories, they make excellent ones and you’re not likely to be disappointed. Drilling performance was excellent with these bits, and we’ll take a closer look at these carbide-tipped concrete eaters later.
Not surprisingly, drilling was a much better experience all around compared to the SDS-Plus hammer I normally use. The upgrade in power was really obvious here as the carbide bit chewed through concrete. I should mention that although Bosch delivers impressive power, I did find one in the 2″ SDS-Max class with higher impact energy, so it’s not quite king of the hill.
The Bottom Line
The Bosch RH1255VC 2-inch SDS-Max rotary hammer is the Cadillac of its class. I certainly recommend it to other professionals. It has the power to weight ratio you need to get the job done and the vibration suppression features that make getting the job done much easier. It takes features and power that look good on paper and translate them into a user experience that you just have to try for yourself. Bosch is known for its quality and the RH1255VC is clearly taking aim at the high end of SDS-Max rotary hammers.
Bosch RH1255VC 2-Inch SDS-Max Rotary Hammer Features
- Turbo Power for torque and speed boost in hammer mode
- Excellent power-to-weight ratio with 14.1 foot pounds of impact energy
- SDS-Max Keyless chuck
- Vibration Control for comfort in all-day applications
- Constant Response for soft start, constant speed under load
- Vario-Lock positioning for precise chiseling location
- Weighs less than 27 lbs
Bosch RH1255VC 2-Inch SDS-Max Rotary Hammer Specifications
- Motor: 15 amps, 120 volts
- No Load Speed: 100 – 220 RPM
- Impact Rate: 1000 – 2150 BPM
- Chuck Design: Keyless, SDS-Max
- Maximum Hole Diameter: 6 inches (core bit)
- Length: 23.5 inches
- Width: 4.5 inches
- Weight: 26.2 pounds
- Includes: Carrying case
- Price: $1099.00
- Warranty: 1 year
