GBH 18V-21 rotary hammer
The GBH 18V-21 is a cordless rotary hammer manufactured by Bosch as part of the Bosch Professional product line.
The machine has a brushless electric motor powered by a 18 volt battery.
According to Bosch the maximum diameter for drilling in concrete is 21 mm, but the optimal range for this machine is 6 to 10 mm.
At 2.4 kg the machine is slightly lighter and slightly more powerful than the GBH V-EC but is sold for a higher price.
Exterior
The machine has a blue plastic body with a black front half and red accents. The machine has a D-shaped handle placed under the motor housing.
Above the handle is a red switch to reverse the turning direction. On front of the handle is a large red trigger switch that can be pressed down with two fingers.
For improved balance the 18V battery is located in the middle under the body in front of the handle. It slides in from the front. The auxiliary handle must be moved out of the way to replace the battery.
Right above the battery is a white LED that shines upwards at an angle to illuminate the working area.
Towards the top on the front is a gearbox with a mode dial on the left side to select the work mode.
At the very front is an SDS Plus chuck in which drills or chisels are inserted.
Behind the chuck is a round neck on which an rotatable auxiliary handle with optional depth gauge is attached.
Operation
The machine is activated by pressing the variable speed trigger switch. The push button above it can be used to reverse the turning direction or as a trigger lock when the button is centered.
The black knob on the left side is used to select the work mode. The knob has four settings:
- Drilling for materials like soft masonry, wood and metal.
- Drilling plus hammering for hard masonry like concrete.
- Chuck adjustment mode allows the chuck to be rotated into another position to adjust the angle of a chisel.
- Hammer only for chiseling and demolition.