SDS-plus Chisel
HERMAN MH-21 Flat Waved
Flat for concrete and masonry

Significantly longer service life compared to standard flat chisels:
- more than 2 times larger working area
- reinforced edges of the work surface with two corrugations to significantly slow down unwanted rounding of the blade edges - the work surface of the chisel retains its shape for longer

Easier release of the chisel when clamped in concrete:
the undulating shape of part of the chisel surface close to the blade reduces friction - releasing a wedged chisel is not as strenuous

Better heat dissipation:
thanks to the larger surface area, the temperature of the working part is lower by several tens of degrees Celsius compared to the pointed chisels of standard design

Greater working comfort:
the shape of the working part contributes to reducing the intensity of vibrations transmitted to the worker's hands

High impact force on the workpiece when chopping:
the kinetic energy of the impact is concentrated in the relatively small width of the chisel blade

High-strength and specially heat-treated tool steel:
for high durability and tool life

Recommendation:
When working, regularly lubricate the chisel shank (preferably every 20mins) with suitable grease. This will prevent overheating and prolong the life of the machine
Maintain at least approximately the geometry of the angles of the working part of the chisel by regular sharpening. You will thus achieve consistently high work productivity with less effort for both machine and operator

Warning:
During chopping and demolition work, the temperatures of the working part of the chisels reach high values - often 200 degrees Celsius or more. Therefore, be careful when changing chisels or lubricating their shanks

Note:
Chisels in this category are often called "self-sharpening chisels". These are features that no chisels suitable for electro-pneumatic hammers have, and to call them this is misleading and deceptive SDS-plus is a trademark of Robert Bosch GmbH, Stuttgart, BRD