The product life cycle is significantly extended by eliminating troubles with armature burnout, layer short and commutator wear. Besides, no carbon brush replacement is required. The efficient brushless motor offers higher drilling performance even with an extension cord used. Designed to be powered by engine generators as well, thanks to Our original compact and high efficiency inverter circuit. The high efficiency brushless motor and the optimized hammering mechanism achieve the fastest drilling speed* and the highest demolition performance* in its class.

As of March 2015. Among 45mm class rotary hammers made by leading power tool manufacturers, surveyed by Koki Holdings.
reduces the vibration from concrete drilling or chiseling by moving a weight and a leaf spring in the opposite direction to the movement of the hammer.provides high vibration-absorbing effect by employing both transatory and hinge units. makes the housing more rigid, significantly enhancing durability of the motor unit.

Approx. 13% Faster Drilling Speed*1
Approx. 28% More Demolition Performance*2

A comparison between the DH40MC and previous model DH40MR. (When drilling ø16-40mm holes into concrete. Actual results vary depending on
conditions.)
A comparison between the DH40MC and previous model DH40MR. (Actual
results vary depending on conditions.) A larger damper and higher volume air cushion reduce the impact and piston reaction force generated during hammering. This results in
significant vibration reduction. It only takes one action instead of conventionally-required two to mount a drill bit. All that needs to be done is insert the drill bit into the tool holder while
turning it. Large change lever located on top of the tool for easy visibility allows smooth mode changing.
– Hammering (for demolition)
– Neutral (for bit angle adjustment)
– Rotation + Hammering (for drilling) The chisel can be rotated at 12 different angles with the change lever
positioned at ‘neutral’.