Makita has announced a new addition to their line of concrete rotary hammers, a two-inch model with enhanced Anti-Vibration Technology (AVT). Earlier this year I saw the 1 9/16-inch version of the tool demonstrated at the World of Concrete (video below) and the AVT appeared to greatly reduce vibration.
According to Makita, many rotary hammers rely on spring-loaded handles to take care of vibration. Their AVT tools rely on a three-component system that deals with vibration in ways simple spring-loaded handles cannot:
An air actuated counterbalance dampens vibration by moving in the opposite direction of the drive piston.
- The upper housing and handle move independently because they’re decoupled from the motor and drive mechanism.
- There is a damper spring at the base of the impact bolt to absorb impact vibrations from the drill bit.
Features include a torque-limiting clutch, soft start, and constant speed control to maintain even speed under load. The two-mode tool has “hammering with rotation” and “chipping only”, with the option to lock the tool on in chipping mode. It offers 24 bit angle settings and a one-touch sliding chuck for fast bit changes.
Makita HR5212C Specs
Motor: 15 amps
Capacity in concrete: 2”
Impact energy: 19 joules (14 ft-lbs)
Vibration rating: 9m/s²
Blows per minute: 1,100-2,250 BPM
Bits: SDS MAX
Length: 23 1/2”
Weight: 26.2 pounds
Includes: rotary hammer, depth rod, bit grease, D-handle, straight handle, and straight handle assembly
Country of origin: Japan
Available: October 2014