CNC Knowledge: How many types of drill bits are there? Eight out of ten people cannot answer the question (image and text explanation)

A drill bit is a rotating tool with cutting capability at the end of the head. It is usually made of SK carbon steel or SKH2, SKH3 high speed steel and other materials, milled or rolled and then ground after quenching and heat treatment. for metal or other materials. It has a wide range of uses and can be used on machine tools such as drilling machines, lathes, milling machines and electric hand drills.

Drill bits can be divided into the following types according to different types:

1

Classified by structure

1. Integrated drill bit: The drill top, drill body and drill handle are all made of the same material.

2. End welded drill: The upper part of the drill is carbide welded.

2

Classification by drill shank

1. Straight shank drill bit: All drill bits with a diameter less than φ13.0mm use a straight shank.

2. Taper shank drill bit: The shank of the drill bit is tapered and the taper is usually Morse taper.

3

Sorted by use

1. Center drill: generally used to reach the center point before drilling. The front end taper has 60°, 75°, 90°, etc.

2. Twist drill: the most widely used drill bit in industrial manufacturing.

3. Super hard drill bit: The front end of the drill body or the whole is made of supercarbide cutting material, used for drilling processed materials.

4. Oil hole drill: There are two small holes in the drill body. The cutting agent reaches the cutting edge through the small holes to carry away heat and chips. When using this drill bit, the workpiece generally rotates while the drill bit remains. stationary.

5. Deep hole drill bit: It was first used for drilling gun barrels and stone-covered pipes. It is also called a gun barrel drill bit. Drill bit specially designed for machining deep holes. In machining, holes with a depth to hole diameter ratio greater than 6 are generally called deep holes. When drilling deep holes, it is difficult to dissipate heat and remove chips, and because the drill pipe is thin and not very rigid, it is prone to bending and vibration. Typically, a pressure cooling system is used to solve cooling and chip removal problems.

6. Drill reamer: The front end is a drill and the rear end is a reamer. The only difference between drill bit diameter and reamer diameter is the amount reserved for reaming. There are also drill bits used in combination with taps, which is why they are also called hybrid drill bits.

7. Taper drill: Taper drill can be used when processing the mold feed port.

8. Cylindrical Hole Drill: We call it a countersunk cutter. The front end of this drill bit has a smaller diameter part called the shank.

9. Tapered hole drill: used for drilling tapered holes. Its front end angle is 90°, 60°, etc. The chamfering tool we use is one of the taper hole drills.

10. Triangular drill bit: A drill bit used in power drills. The handle of the drill is made into a triangle so that the chuck can firmly fix the drill bit.