different role of core drill bits

First, tell us about this twist , because there are too many types of drills to say , how to understand the difference with other drill twist it ? It is understood that twist the words of the working GUSHI concrete polishing pads  portion has two spiral grooves , the shape of cannabis, hence the name. Secondly , taper shank twist on extended structure, there is the use of what are the advantages? 1 Typically the diameter range of 0.25 to 80 mm . It is mainly composed of a working portion and a shank portion . 2 In order to reduce the guide portion and the hole drilling intramural friction , twist from the direction of the drill tip to gradually reduce the diameter of the shank inverted cone . 3 major influence extended helix angle taper shank twist angle  GUSHI metal grinding wheel of the cutting edge approached the size , strength and chip performance edge flap , typically 25 ° ~ 32 °. 4 spiral groove available milling, grinding , hot-rolled or hot extrusion processing methods such as forming part of the cutting tip drill by grinding . 5 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  GUSHI diamond polishing tools middle , chisel at a negative rake angle ( up to about -55 °), from the squeezing action when drilling . 6 In order to improve the taper shank twist drill cutting lengthened , according to the nature of the processed material will be ground into a variety of cutting part of the revised shape . Not to mention longer taper shank twist drill with efficient appreciation of space, but it is worth it value into the ......