Multi-blade plate drill from the material there are two main categories: high speed steel plate are drilled, and the other is carbide steel drill. High speed steel plate drilled with good stability and abrasion, is the main series; carbide steel drill with higher cutting speeds, complex material can be done well drilling.
Hollow drill (also known as core drilling, drilling steel, hole drilling), the standard name for blade plate drilling. Is a form of multi-blade circular cut, using the drill cutting hole diameter annular part, do not cut the middle section, thus greatly increasing the drilling efficiency, and magnetic drill, boring job site can be achieved at any time, as opposed to ordinary twist drill, higher efficiency, and cutting the light. Hole diameter from 12mm to 150mm, depth of 25mm, 35mm, 50mm, 75mm, 100mm, 150mm, 200mm, and so on.