What Is a Rotary Hammer Drill?
A rotary hammer drill is a power tool used for drilling and cutting holes in hard materials, such as concrete and stone. They are mainly used for construction and civil engineering work.
General electric drills use the rotation of a motor to tighten screws or drill holes in wood, steel, and other materials. A rotary hammer drill, however, not only rotates but strikes vertically against the drill blade. These blows create a strong impact on hard concrete while drilling holes in it. Also, when only impact is used, strong vibration allows the drilling of concrete and stone materials as if a hammer is hitting them.
Uses of Rotary Hammer Drills
Rotary hammer drills are most commonly used for drilling in concrete and stone. The basic function of rotary hammer drills is for powerful drilling by rotation and impact. However, some products can be used in three different modes: rotation only, impact only, or rotation and impact only.
Rotation and impact are used for drilling holes for anchor bolts to secure a structure or equipment to concrete. Core drilling can also be used to penetrate walls and floors for electrical, HVAC, and other piping. The appropriate bit (drill bit) is needed for each of these tasks.
When only hammering is used, it can be used to break concrete and peel tiles. For drilling, use a special tool for striking and a chisel tip tool.
In the case of rotation only, holes can be drilled in wood, steel, and other materials in the same way as with a regular electric drill.
How to Select Rotary Hammer Drills
Here are some points to consider when choosing rotary hammer drills. Select a model according to the object to be drilled, the location of use, and other uses of the drill.
- Difference Between Rechargeable and Power-Supply Type
Rotary hammer drills are available in two types: those that use AC100V power from an outlet and cordless types that use rechargeable batteries. The cordless type, while slightly less powerful than the AC100V type, can be used in places where there is no power supply, and the workability is improved because there is no need to worry about the power cord. However, the battery needs to be recharged. - Maximum Drilling Capacity
Rotary hammer drills have a maximum drilling capacity. Each model has a maximum drilling capacity of up to a certain number of millimeters in diameter. The drilling capacity value is also set according to the type of bit used and the rotation mode. It is necessary to check the applicable cone diameter depending on the uses of the drill. - Dust Collection Capacity
When drilling holes in concrete, stone, and other materials, the problem is the dust that is blown into the surrounding area. Some models are equipped with a dust collector to prevent this dust. With a dust collector, dust is sucked up while drilling, preventing it from scattering, which makes it effective for indoor use. It is so necessary that there are some construction sites where it is not possible to bring in a machine without a dust collector. Some models come with a dust collector, while others can be retrofitted (sold separately). - Functions Other Than Rotation and Blow Mode
Rotary hammer drills are primarily used in rotation and blow mode. However, if there is a mode switch for rotation only or impact only in addition to rotation and impact, it can be used for work other than drilling. In particular, hammering work in impact-only mode is not possible with vibration drills or impact drivers. It can also be used for tile removal, concrete excavation, and digging up hard soil.