How to choose diamond core drills according to different uses

DrillWe drill is widely used in construction machinery hardware, it is used in the drilling of solid material through holes or blind holes , and is able to have the hole reaming tools. However, we choose different operating environments are also different types of drill bits , drill bits used mainly twist , flat drill, center drill , deep hole drilling and core drill . Reamer and countersink drill , although not on the physical material drilling, but the habit will also drill them into a class . Here , together with Xiaobian look at different types of drill bits for different uses of it .
Twist is the most widely -processing tool . Diameter in the GUSHI concrete polishing pads  range of usually 0.25 to 80 mm . It is mainly composed of a working portion and a shank portion . Working part has two spiral grooves , the shape of cannabis, hence the name. In order to reduce the wall of the guide portion and the hole drilling friction , twist from the direction of the drill tip to gradually reduce the diameter of the shank inverted cone . Twist the helix angle corner came mainly affect the size of the cutting edge , edge flap strength and chip performance , typically 25 ° ~ 32 °. Available spiral groove milling, grinding , hot rolling or hot extrusion processing methods , the cutting portion is formed by sharpening the drill tip . Vertex standard twist drill cutting part 118 , chisel edge angle is 40 ° ~ 60 °, the angle of 8 ° ~ 20 °. For structural reasons , the rake angle at the outer edge of the large decreases toward the middle , chisel at a negative rake angle ( up to about -55 °), from the squeezing action when drilling . In order to improve the cutting twist drill , according to the nature of the material to be machined and ground into the cutting portion of the repair various shapes ( such as drilling group ) . There shank twist and form two straight shank taper shank , when caught in the drill chuck machining the former , the latter is inserted in the machine spindle or tailstock taper in . General manufacturing HSS twist drill . Inserts welded carbide blade or twist the crown for machining cast  GUSHI tile cutting blades iron , hardened steel and non-metallic materials , solid carbide twist drills for machining small parts and printed circuit boards and other instrumentation .
Flat diamond cutting part Spade, simple structure, low cost, easy to import coolant hole, but cutting and chip performance is poor . Flat structure with integral drilled and assembled two. Integral mainly for drilling diameter of 0.03 to 0.5 mm pores . Fabricated flat diamond blade can be changed, the cooling can be mainly used for drilling large diameter holes 25 to 500 millimeters.
Deep hole drilling process usually refers to the ratio of the aperture hole depth and hole cutter more than 6 . Commonly used gun drilling , BTA deep hole drilling, jet drilling , DF deep hole drilling. Nesting also commonly used in deep hole drilling process .
The reamer 3 to 4 teeth , better rigidity than the  GUSHI cutting discs twist drill , a hole has been used to expand and improve the machining accuracy and finish .
Countersink drill has more teeth to the hole forming method will be processed into the desired shape of the end for the processing of various countersunk head screws countersunk holes , or outer end face flattened hole.
Center drill for drilling shaft center hole with a piece , which is essentially a small twist of the helix angle drill and countersink compounded , so called composite center drill.
Hollow drill drill drill pipe is hollow in the middle , the main material used for core drilling .