Specification | Length | Cutting length | Work length | Shank diameter |
13/64 HSS drill bit | 92mm | 62mm | -- | 13/64" |
Straight shank twist HSS drill bit composition.
Twist drill according to its different functions, can be divided into three parts:
1. The handle, the part of the drill for the fixture, and convey the power (torque and axial force) required to borehole.
2. Drill neck, located between the blade body and the transition between the shank part. It is usually used as an empty knife slot for wheel retraction.
3. Drill body, drilling bit work part. Consist by the cutting part (ie drill tip) and the guide part.
Straight shank twist HSS drill bit parameters
In order to reduce the friction between the guide part and the hole wall during drilling, the straight handle twist drill is gradually reduced in diameter from the tip to the shank. The helix angle of the straight shank twist HSS drill bit mainly affects the size of the cutting edge rake angle, the flap strength and the chip removal performance, usually 25 ° ~ 32 °.
The helical groove can be machined by milling, grinding, hot rolling or hot extrusion. The front end of the drill bit is sharpened to form a cutting part. The cutting part of the standard straight shank twist HSS drill bit has a vertex angle of 118°, a horizontal bevel angle of 40 ° to 60 ° and a rear angle of 8 ° to 20 °.
Due to structural reasons, the rake angle at the outer edge of the large, gradually reduced to the middle, the horizontal edge at the negative rake angle (up to -55 °), when drilling from the extrusion effect. In order to improve the cutting performance of the straight handle twist drill, the cutting part can be machined into various shapes (such as group drills) according to the nature of the material being processed.
The shank of HSS drill bit with two types: straight shank and taper shank(morse taper), when machining,the former is caught in the drill chuck, the latter inserted in the machine tool spindle or tailstock cone hole.
Straight shank twist HSS drill bit maintenance
1. When drilling steel, please ensure adequate cooling and use metal cutting fluid.
2, a good drill pipe steel and rail clearance can improve the accuracy of drilling and drill life
3, to ensure that the magnetic seat and the workpiece between the smooth and clean.
4, drilling sheet, to strengthen the workpiece, drilling large parts, please ensure that the workpiece is stable.
5, at the beginning and end of the drilling, the feed should be reduced by 1/3.
6, the drilling of a large number of fine powder material, such as cast iron, cast copper, etc., can not use the coolant, and the use of compressed air to help chip removal.
7, please promptly remove the iron filings wrapped in the drill body to ensure smooth chip removal.