Drills can be divided into three categories: hand drill, impact drill, hammer drill.

1. Hand drill: the smallest power, the scope of use is limited to drilling wood and when an electric screwdriver, some hand drill can be changed according to the purpose of specialized tools, use and model more

2. Impact drill: The impact of impact drill mechanism has two types of dog teeth and ball

  Hand drill

3. Ball-impact drill by the moving plate, plate, steel balls and other components. The moving disk is connected with the main shaft through threads and is provided with 12 steel balls. The fixed disk is fixed on the casing by pins and has 4 steel balls. Under the thrust force, 12 steel balls roll along 4 steel balls, Carbide drill to make rotary impact movement, in bricks, blocks, concrete and other brittle materials on the drilling. Take off the pin so that the fixed disk follow the rotation with the disk, does not produce impact, can be used for ordinary electric drill.

Hammer drill (hammer): can drill holes in a variety of hard materials, the most widely used.