Things to note when using twist drills

There are many drilling tools on the market at present, mainly including ordinary twist drills, indexable shallow hole drills and flat drills. When drilling with a machining center, an ordinary twist drill is usually used. The ordinary twist drill is mainly composed of a working part and a handle. The tool shank is available in two types: straight shank and tapered shank. The handle of straight-shank tools is mainly a spring chuck handle, which has the advantages of automatic centering and automatic elimination of deflection, so it is best to use this type for small-sized tools. The working part includes the cutting part and the guide part. The cutting part of the twist drill has 2 main cutting edges, 2 secondary cutting edges, and 1 chisel edge. The guide part of the twist drill serves the functions of guiding, polishing, chip removal and transporting cutting fluid. Twist drills are generally used for rough machining of holes with low precision. Since the fixture used in the machining center does not have a drill sleeve centering guide, the drill bit is prone to yaw movement during high-speed rotation and cutting, and the chisel edge of the drill bit is long, so when drilling , use a center drill to drill the center hole to guide the drill bit. When using twist drills, you should pay attention to the following points:

1. What is the difference between a straight handle twist drill and a tapered handle twist drill? What are they mainly used for? Twist drills are generally divided into: straight shank twist drills and tapered shank twist drills. The difference between them is: straight shank twist drills generally use drill cards to clamp the drill shank processing parts, straight shank twist drills and tapered shank twist drills drill the tail of the shank. It has a flat tongue and can be directly clamped to the machine tool for processing components, or it can be clamped to a drill sleeve and then clamped to the machine tool for processing components. The tapered shank twist drill usually uses a straight shank for small drills and a tapered shank for large drills.

2. When using a twist drill to process some high-hardness, thicker metal plates and stainless steel, the drilling speed should be controlled and the rotation speed should not be too fast. At the same time, coolant should be used, which is more conducive to the twist drill.

3. Twist drill bits should be packed in special packaging boxes to avoid vibration and collision with each other. When in use, the drill bit should be taken out of the packaging box and immediately installed into the spring chuck of the spindle or the tool magazine that automatically replaces the drill bit.

4. Frequently check the concentricity of the spindle and spring chuck and the clamping force of the spring chuck. Poor concentricity will cause small-diameter drill bits to break and large hole diameters. Poor clamping force will cause the actual rotation speed and settings to change. The rotational speed does not match, and there is slippage between the chuck and the twist drill bit.

5. Check the spindle presser foot frequently. The contact surface of the presser foot should be horizontal and perpendicular to the spindle and should not sway to prevent drill breakage and eccentric holes during drilling.

6. Timely regrinding can increase the use and regrinding times of twist drill bits, extend the life of the drill bit, and reduce production costs and expenses.