Rotary hammer drills are better for drilling in concrete. The combination of hammering and cutting action ensures a smooth hole in the concrete.
We’ll see what are the best rotary hammer drills in the market today. Scroll down below for the suggestions.
Before that, we have to identify the difference between rotary hammer drills as compared to regular hammer drills.
Also, below are some ideas on when you should actually use a rotary hammer drill.
Rotary Hammer Drills Vs Hammer Drills
Rotary hammer drills should be used wherever the hammer drill fails. They utilize a separate mechanism to deliver greater impact energy to the drill bit. Rotary hammer drills therefore provide more energy in each hammer blow. This makes drilling into the concrete much easier and faster.
Rotary hammer drills uses special slotted drive system (SDS) drill bits whereas the hammer drill uses a 3-jaw chuck. These SDS drill bits have slots in the shank of the bit.
The slots engage with special pins in the SDS chucks. These slots allow the drill bit to be retained in the chuck without falling out.
At the same time, another pair of slots allow the drill bit to move to and fro in the chuck. The drill bit is therefore free to slide and requires lubrication for proper functioning.
How more impact energy is delivered to the drill bit
This is usually achieved using a piston driven by a crankshaft. The motor drives a crankshaft which oscillates a piston within a cylinder.
The piston compresses the air trapped between it and a striker ram. This high pressure air pushes forcibly the ram which then hits the drill bit. The drill bit is pounded into the concrete.
As the drill bit also rotates, the cutter at the tip of the drill bit cuts into the concrete mass. The loose cuttings at the tip are then moved via the flutes of the drill to the concrete surface from the hole. This joint hammering-cutting method has proven very effective.
The rotary hammer drill uses a special SDS chuck which requires SDS drill bits. It has no jaws as can be found in the chuck of the hammer drill.
The SDS drill bit has slots in its shank which engages with the special SDS chuck. When fitted in the chuck, the SDS drill bit is actually able to slide to and fro in the chuck.
This free motion allows for a bigger hammer impact in this device and ensures better drilling in concrete.
Modes of Operation
Most rotary hammer drills can operate in one of three modes:- drill mode, hammer- drill mode or just hammer mode. In the hammer mode, the device works like a mini-jackhammer.
Selector for drill / Hammer drill/ hammer mode
Most rotary hammer drills can also be operated as a normal drilling as well as a mini jackhammer. This is done by simply pushing a selector into ‘drill’ or ‘hammer drill’ or ‘hammer’ mode.
In ‘drill’ mode, the drill operates like a normal drill which rotates only.
In ‘hammer drill’ mode, and using a masonry drill bit, the device is good for concrete. In ‘hammer’ mode, the chuck does not rotate but the chuck merely moves to and fro only.
Best rotary hammer drills
Below are some of the top rotary hammer drills you can acquire today.
1. BOSCH 1-1/8-Inch SDS Rotary Hammer RH328VC
Bosch is a well known brand for power tools and rotary hammer drills aren’t an exception.
Below are some of the advantages of Bosch’s rotary hammer.
Why buy the Bosch rotary hammer drill?
- Bosch is a German multinational brand of good standing
- Delivers high level of impact energy with good vibration control
- Provides 3 modes of operation :- rotation only, hammer only, drill + hammer
- Features an integral clutch, which disengages the torque transmission if the bit gets into a bind-up situation
- Has variable speed (0 to 900 rpm) three finger trigger
- Depth gauge sometimes slips. This can cause longer holes
2. DEWALT (D25263K) Rotary Hammer Drill
Dewalt is another brand that specializes in power tools for both household and industrial uses.
Their rotary hammer is also recommended for the following reasons.
Why buy the Dewalt rotary hammer drill?
- Has 8.5A rotating brush ring motor and which delivers appreciable amount of impact energy
- D-Handle has vibration dampers reduces fatigue
- Has integral clutch which reduces over-drive and also reduces injury to user
- Some reports of drill getting hot after some working with the drill
- Uses SDS shanks of 10mm diameter only. Not 1 inch shanks
3. MAKITA HR2475 1″ Rotary Hammer
This Makita rotary hammer is made with their own Makita Motor Advantage engineering. They help to deliver a more efficient transfer of energy which gives better power and is able to last longer.
Why the Makita rotary hammer?
- Powerful 7A motor which delivers up to 4500BPM hammer beats
- 3 mode operation:- drill mode, drill+ hammer mode, Hammering only
- Built-in torque limiter ensures good control
- D shaped handle with rubberised soft grip for comfort and control
- multiple chisel positioning allows work flexibility
- Must be mindful not to operate the “locked on” button unintentionally. This causes the drill to work unstoppably even when you release the trigger
- Isolated case of motor overheating when used for mixing paints
4. ENEACRO Heavy Duty Rotary Hammer Drill
This Eneacro rotary hammer is for 1 – 1/4 inch and it comes with a power 12 Ampere motor.
They have many features including a safety clutch, varying functions that can be used for different purposes and a good drilling capacity.
Advantages of the Eneacro rotary hammer drill
- Powerful 12A motor which creates good impact energy
- 4-modes of operation :- drill, hammer, chisel, hammer+drill
- 2 mode-switches provided to select the mode of operation
- Heat dissipation system incorporated to ensure cool operation
- Some reported cases of motor overheating issues during initial use. Was given new set in good time
- Manual was brief and did not explain how to use the 2 mode-switches
- Does not come with a depth gauge
- Does not have “Reverse” function
5. KIMO 20V, 1 Inch, SDS Plus Rotary Hammer Drill
KIMO may not be as well known as brands like Dewalt or Bosch but they can stand on their own.
It’s much newer and they’ve received lots of great reviews so far.
Why buy the KIMO rotary hammer drill?
- Brushless motor with adequate impact energy
- 3 modes of operation:- drill, drill + hammer, hammer only
- Cordless drill gives more flexibility
- Rapid charging within 1 hours available
- good vibration control gives comfortable handling
- New product. No big complaints
6. Milwaukee SDS Plus Rotary Hammer
Why is the Milwaukee rotary hammer good?
- Popular American brand of long standing
- Highly durable, easy to use and handle
- Brushless motor and battery powered, convenient and cordless
- Very good power even when handling 1 inch drill bits
- Cheap plastic construction for the price paid
Buying Guide For Rotary Hammer Drills
Below are some ideas on whether you need a rotary hammer drill for drilling concrete.
Why a hammer drill?
If you are drilling a hole in concrete using a normal rotating drill, you will soon realize that it is impossible. The drill bits will wear out in no time. The hole is hardly progressing.
You will soon be rushing to buy a hammer drill. For drilling through hardened concrete, you will definitely find this drill essential.
If hammer drills aren’t sufficient, what should you use?
If your concrete drilling requirements are more numerous and quite frequent, a hammer drill may not work well. In these cases, rotary hammer drill is definitely required. The rotary hammer drill uses a special chuck (SDS) wherein the SDS drill bit can actually slide to and fro like a hammer in the chuck.
The energy delivered per hammer beat is also much greater. The drilling is better accomplished and in shorter time.
Corded or cordless?
The next consideration could be whether it should be the corded type or the cordless variety. Everyone has their considerations. These include whether the job area usually has electrical outlets.
The corded type needs to be connected to the electrical supply. The corded type is generally accepted as being able to give a higher torque for the same size of drill.
Do you need to attend to some jobs which are located far from an electric outlet? This is where the cordless is supreme. No need to look for an extra long extension cord.
Many users have bought both types. This way they can use the appropriate type that the particular situation demands.
You need SDS drill bits for concrete
Undoubtedly you also need to have proper SDS drill bits. Some people felt that the drill is only as good as the drill bit. So a good drill bit goes a long way.
You should consider having carbide tipped drill bits. This carbide bit retains its cutting edge for long time even when used in heavy duty and over a long period of time. It ensures less downtime where new drill bit must be purchased.
Which rotary hammer drill to buy?
The market is full with many brands. This part of the market is highly competitive. Many of the brands will offer products with features that are competitive with the others.
So it is probable that one brand will not drastically be different from the other.
Some are corded while others are cordless. Many DIY householders ended up with both types in their garage.
It is likely that although the brand is American or German, China produced parts are used. Since China is regarded as the world’s factory, it will have produced many of the parts that are assembled into the final drill.
While these are usually practical and robust, many users find that many of these lack precision. However they are adequate for most if not all household projects.
Bare tool or complete with accessories
It may not advisable to merely buy just the bare tool. Bare tool means that you only get the drill without the accessories.
You still need to purchase accessories such as drill bits, concrete drills, holding bar and others. If Amazon or other stores offer a drill together with accessories in a package, it is definitely better than buying them separately.
Buying this way usually ensures that the accessories will fit the drill that it comes with. Much time can be lost trying to find out whether the accessories will fit the bare drill that you bought.
Buyers buy with different reasons. Some are recommended by the friends or colleagues. Some buy the same brand to replace their older same brand tool which they are happy with.
Others buy the different brands because they are not happy with their current brand. Many buy when the price feels good and right.
So the one with the features and looks which appeals to you and also has the right price is probably the right one for you. Good luck.