GBH 18V-45 C rotary hammer
The GBH 18V-45 C is a heavy duty 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. In February 2022 it was the most powerful rotary hammer for the Bosch Professional 18 volt battery system
The machine can be used to drill holes up to 45 mm in diameter in concrete. According to Bosch the optimum diameter for drilling in concrete is 20 to 40 mm.
Bosch does not specify a maximum diameter for drilling in wood and metal since that is not the intended use for this machine.
Exterior
The machine has a blue plastic body with black parts and the controls have red accents. The machine has a D-shaped handle placed behind the motor. It is connected through a flexible joint on top to reduce vibrations being transferred from the machine body to the handle.
Above the handle is a red lock button. On front of the handle is a large red trigger switch that can be pressed down with multiple fingers.
The 18 volt battery has an unusual sideways position and slides in from the left. Although the battery charge indicator on the back of the battery can be accessed it is not in a convenient place.
The machine has its own battery charge indicator on the back of the body in front of the handle (not visible in picture). The battery charge indicator consists out of five LEDs. The first LED can be red, orange or green depending on how far depleted the battery is. The four others are only green.
Besides the battery charge there is also an overload and kickback control indicator LED on the same panel.
Below the battery is a white LED that is angled upwards to illuminate the working area. If the auxiliary handle is position downwards it will block some of the light.
On the sides of the motor housing is the Bosch logo and model name.
On top of the motor housing is a black knob that is used to change both the the work mode and turning direction.
In front of that is a relatively long cylindrical neck around which the collar of the rotatable auxiliary handle is secyured. There is no depth gauge.
At the very front is an SDS Max chuck in which drills or chisels are inserted.
Operation
The machine is activated by pressing the trigger switch. The red lock button above the trigger can be used to lock the trigger so that the machine keeps running. This is particularly useful when chiseling.
The black knob on the top is used to select the work mode an turning direction. The knob has four settings:
- Drilling plus hammer spinning counter clockwise (reverse).
- Drilling plus hammering spinning clockwise (forward).
- Chuck adjustment mode allows the chuck to be manually rotated into another position to adjust the angle of a chisel.
- Hammer only for chiseling and demolition.
Under the battery charge indicator there is a membrane button to select a work mode. Below it are three labels: Auto, Soft and Favorite.
In Auto mode the machine will use maximum power but with soft start and kickback control features enabled.
The Soft mode is meant for working on delicate materials and will ramp up the speed more slowly up to 80% of the maximum.
In Favorite mode the settings that are set using the smartphone app will be used.
Bluetooth connectivity
The machine has a built-in wireless communication module in the handle that uses Bluetooth to connect to the Bosch Toolbox app on a smartphone to adjust some settings.
The module is located behind a round over on the left side of the motor housing. The cover can be opened by twisting it with a coin. The module can be removed so that the machine can also be used in environments where wireless communications are restricted.
Safety
The machine has soft start feature and electronic kickback control which will disengage the machine if a sudden twisting motion is detected.