The 25701K ... low vibration levels.

Leading international industrial power tools and accessories manufacturer DeWalt has launched two new hammers which are claimed to set a new benchmark in comfort and performance in their class.

These include the D25900K, which is described as “the most comfortable, durable and productive 10 kg demolition hammer in the world” and the D25701K combination hammer, “the most comfortable and powerful, and lowest vibration SDS-max hammers in its class”.
“The new D25900K breaks everything from hard concrete to clay faster, and more accurately and safely than any other comparable tool on the market,” says Suresh Srinivasan, product manager, Middle East and Africa DeWalt Industrial Tools. “For increased durability, the D25900K is powered by a large optimised hammer mechanism with an innovative dust-protection system, driven by a new 1,500 W leaded motor.
DeWalt claims that this new hammer is also the most productive in its class.
“The D25900K uses an optimised hammer system that balances impact energy and beat frequency to break concrete and masonry in the most efficient way possible. Combining 750 W of output power with a single-blow impact energy of up to 25 joules, it can achieve breakage rates of 900 kg of concrete per hour.  In fact, our tests have shown that it breaks over 100 kg more material per hour than any other 10 kg demolition hammer,” Srinivasan states.
The innovative Active Vibration Control (AVC) system in the new demolition hammer has improved user comfort and safety as it ensures operators are never subject to vibration levels of more than 9.8 m/s2, ensuring safer and comfortable use for longer periods and therefore increased productivity.

Combination hammer
Turning to the new combination hammer, Srinivasan says: “The D25701K comprises many new features that make drilling and breaking safer for the end-user and meets the European Physical Agents Directive 2002/44/EC for Hand Arm Vibration (HAV).”
“The D25701K has a x-axis vibration level of only 5.4m/s2 (only 9.9 m/s2 tri-axial level) which means it can be used for more than double the time of most comparable competitive machines available on the market. The low vibration levels are derived from the AVC system used inside the machines,” he explains. “The first AVC is the spring-loaded weight that counterbalances the movement of the hammer mechanism, reducing the tri-axial vibration by up to 30 per cent. The second is the floating rear handle that is spring loaded and linked between top and bottom through a steel rod. With this in place, no matter where the rear handle is pressed, the whole handle is completely dampened from top to bottom, helping to reduce x-axis vibration by over 70 per cent.”
Another new safety feature in the combination hammer is the Complete Torque Control (CTC) that has been included in response to end-users requirements for a clutch system with lower torque but with the option for high torque, whenever needed.
“This is particularly useful for those that drill a variety of different-sized holes. The low torque setting is perfect for 12 to 40 mm holes and the high torque setting is suitable for holes of 40 mm or more, especially core drilling up to 125 mm. The torque system is completely mechanical, thus making it more reliable than electronic clutches. The unit clutches out, alerting the operator of the problem without switching the unit off and only operates when required,” he says.
The D25701K is ideal for drilling anchor fixings and through-holes up to 48 mm and core drilling from 40 mm to 125 mm and has rotation stop for demolition applications in brick, block and concrete, Srinivasan says.
Other products in the range are the D25840K, the chipping-only version that is suitable for demolition applications and the D25700K, a standard-feature SDS max combination hammer. Both feature low vibration with a floating rear handle in their product designing.