Drill bit is a tool used to drill through holes or blind holes in solid materials and can also enlarge existing holes. The commonly used drill bits mainly include twist drill bit, flat drill bit, center drill bit, deep hole drill bit and nesting drill bit. Although reamer and spot facer cannot drill on solid materials, they are traditionally classified as drill bits.
A. Classification by Structure
1) Integral drill bit: the drill top, drill body and drill handle are made of the same material as a whole.
2) End welded drill bit: the drill top part is welded by carbide.
B. Classification by Drill Hole
1) Straight shank bit: straight shank is used when the diameter of the bit is less than 13mm.
2) Taper shank bit: the shank of the bit is tapered. Generally, its taper adopts Morse taper.
C. Classification by Use
1) Center drill: it is generally used to drill the center point before drilling. The front conical surface has 60 °, 75 °, 90 °, etc. in order to support the tailstock during lathe operation, the 60 ° center drill should be matched with the 60 ° top center of the tailstock of the lathe.
2) Twist bit: it is the most widely used bit in industrial manufacturing.
3) Super-hard bit: the front end of the drill body or all of it is made of super-hard alloy tool material, which is used for drilling for processing materials.
4) Oil hole drill bit: there are two small holes in the drill body. The cutting agent reaches the cutting edge through this small hole to take away heat and chips. Generally, the working object of the drill rotates while the drill is stationary.
5) Deep hole drill bit: it was first used for drilling barrel and stone tube, also known as barrel drill bit. The deep hole drill is of straight groove type, cutting a quarter of the round tube to produce edge chip removal.
6) Drill reamer: for the needs of mass production, its front end is drill bit and the end is reamer. The diameter of the drill bit and the reamer is only less than the allowance for reaming. There is also drill bits mixed for screw tapping, so it is also called mixed drill bit.
7) Taper bit: when machining the feed port of the die, a taper bit can be used.
8) Cylindrical hole drill bit: we call it countersunk milling cutter. There is a small diameter part at the front end of this bit, which is called track rod.
9) Conical hole drill bit: for drilling conical holes, its front end angles are 90 °, 60 °, etc. The chamfering cutter we use is one of the conical hole drill.
Post time: Nov-05-2021