The standard common twist drill has a cutting part vertex angle of 1 18, a cross blade bevel angle of 40 ~ 60 and a back angle of 8 ~ 20. Due to structural reasons, the rake angle is larger at the outer edge and gradually decreases towards the middle, and the rake angle of the transverse edge is negative (up to about-55), which plays a squeezing role during drilling. In order to improve the cutting performance of twist drills, the cutting parts can be ground into various shapes (such as group drills) according to the properties of the processed materials.

There are two kinds of handles for twist drills: straight handles and tapered handles. When machining, the former is clamped in the drill chuck, and the latter is inserted into the cone hole of the spindle or tailstock of the machine tool. General twist drills are made of high-speed steel. Twist drills with cemented carbide blades or crowns are suitable for processing cast iron, hardened steel and nonmetallic materials, and integral cemented carbide small twist drills are used for processing instrument parts and printed circuit boards. . At present, twist drills are widely used in automobile manufacturing, logistics, molds, machinery and other departments. With its more and more extensive application in all aspects, the requirements for application are getting higher and higher. A good brand is inseparable from the support of trademarks. Without trademarks, it will be difficult for enterprises to open the market, so they are divided into 45 categories of trademarks.

Through the trademark classification query, we know that there are no service items about twist drills in the 45 categories of trademark classification. The trademark categories related to twist drills are divided into the seventh category of mechanical equipment and the eighth category of hand tools according to their attributes.

Class 7 machinery and equipment:

0742- metalworking machinery

070 125: drill bit (machine part)

070428: Drill chuck (machine part)

070449: Drill bit (machine part)

Category 8 Hand-held instruments:

0807- Non-electric hand tools

0800 16: drill bit (hand tool part)

080 108: drill bit (hand tool part)

080 197: drill bit (hand tool)