ThomasH
Gold Member
Obed -
To clear up some of the confusion, there are two common types of "hammer drills". One is a rotary percussion drill, which basically is a motor turning a shaft and with a piston actuator, which is made to drill concrete. It drills mainly by striking the concrete with the bit, but also turns the bit to eject the spoils. The second type is a drill that has a sawtooth mechanism that causes the chuck to move in and out a small amount, and primarily drills by turning the bit, but that action is aided by the ratchet mechanism.
The rotary percussion drills typically use spline or sds shank bits, and those are specially shanked to fit a specially designed chucks, which much heavier duty than a typical twist drill chuck. Twist drills are used in a non-percussion drills with a standard chuck, and are lighter duty.
Both work fine for smaller holes, and as a matter of fact, for tapcons, twist bits are much more commonly available and used. Bosch for instance makes some called "blue granite" which are sold at Lowes.
For larger holes in concrete, rotary percussion drills are typically used with their special chucks (sds or spline).
Tom
To clear up some of the confusion, there are two common types of "hammer drills". One is a rotary percussion drill, which basically is a motor turning a shaft and with a piston actuator, which is made to drill concrete. It drills mainly by striking the concrete with the bit, but also turns the bit to eject the spoils. The second type is a drill that has a sawtooth mechanism that causes the chuck to move in and out a small amount, and primarily drills by turning the bit, but that action is aided by the ratchet mechanism.
The rotary percussion drills typically use spline or sds shank bits, and those are specially shanked to fit a specially designed chucks, which much heavier duty than a typical twist drill chuck. Twist drills are used in a non-percussion drills with a standard chuck, and are lighter duty.
Both work fine for smaller holes, and as a matter of fact, for tapcons, twist bits are much more commonly available and used. Bosch for instance makes some called "blue granite" which are sold at Lowes.
For larger holes in concrete, rotary percussion drills are typically used with their special chucks (sds or spline).
Tom