A drill, an impact drill, a rotary hammer and a demolition hammer can look alike, but they do different jobs. The difference is how the tool hits the material, if it hits at all.
How each one works
Drill (rotary drill): the chuck only turns. It drills wood, metal and plastic, and drives screws. It is not made for brick or concrete.
Impact drill: the chuck turns and, with the hammer setting on, also moves back and forth in many small, light blows. The blows are counted in beats per minute (bpm). It drills brick and masonry and can still drill wood and metal with the hammer setting off.
Rotary hammer: a piston drives fewer, much heavier blows into the bit while it turns. The blow strength is given in joules (J). It is the tool for drilling concrete, and most also have a chiselling mode with the rotation stopped. Bits use an SDS plus shank, not a round shank.
Demolition hammer (breaker): it does not turn at all. It only chisels and breaks concrete, brick and stone, with heavier blows than a rotary hammer.
The four Bosch Standard Line tools side by side
BM 370
ID 500
BH 426
SH 500
Type
Drill
Impact drill
Rotary hammer
Demolition hammer
Power
370 W
500 W
800 W
1,100 W
Turns
Yes
Yes
Yes, or off for chiselling
No
Hammer action
No
Up to 48,000 bpm
4.5 J at 4,500 bpm
11 J at 3,950 bpm
Bit holder
10 mm keyless chuck
10 mm keyed chuck
SDS plus
Hex 17 mm
Largest hole
Steel 10 mm, wood 20 mm
Masonry 13 mm, concrete 10 mm, steel 10 mm, wood 25 mm
Concrete 26 mm
Chiselling only
Weight
1.4 kg
1.7 kg
4.3 kg
6.2 kg
Figures are from Bosch's specifications for each model.
Which one do I need?
Wood, metal, plastic and screws only: a drill such as the Bosch BM 370.
Mostly wood and metal, with some holes in brick for fixings: an impact drill such as the Bosch ID 500. It covers both, with the hammer setting on or off.
Regular holes in concrete, or holes bigger than 13 mm in masonry: a rotary hammer such as the Bosch BH 426. It also chisels out small areas, for example for wiring and pipe chases.
Breaking floors, walls and concrete: a demolition hammer such as the Bosch SH 500. It does not drill.
Before you buy
Match the bits to the holder. A rotary hammer needs SDS plus bits and chisels; a demolition hammer needs hex 17 mm chisels; drills and impact drills take round-shank bits in their chuck.
Check the largest hole you need against the table, in the material you will drill.
Think about weight if you will work overhead or for long periods.
