Material selection for twist drills

1. Material is metal:

Copper is a relatively soft metal. You can drill holes on it with ordinary metal drill bits, such as carbon steel drill bits. This kind of drill bit is cheap on the market, and it is easy to drill copper. Although I have not drilled a copper, I know that the Mohs hardness of pure copper is only 3, pure aluminum is lower at only 2, and iron is 4. Copper has good electrical conductivity. Most coppers are of high purity. Although pure aluminum has low hardness, aluminum alloys are often used in production. The hardness of this alloy is greatly improved, so we feel that aluminum is harder than copper in daily life.

Iron is added with carbon, ranging from 0.0218% to 2.11%, to form a carbon alloy. It is also called carbon steel. It generally contains a small amount of silicon, manganese, sulfur, and phosphorus. Generally, the higher the carbon content in carbon steel, the greater the hardness. Note that the carbon content here refers to the previous range, and the higher the strength, the lower the plasticity. That is, the harder it is, the easier it is to break, and the less likely it is to deform. You can understand it by just tapping your head. Only a drill bit that is harder than the material can make a hole easily. This is the basis for choosing a drill bit according to the material.

Twist drill:

Twist drill bits are currently the cheapest and most mass-produced type. The materials of drill bits are generally low-carbon steel, high-carbon steel, high-speed steel, cobalt steel, tungsten carbide, etc. Low-carbon steel can be used to drill copper, high-speed steel drill bits can be used for steel materials, and cobalt drill bits can be used for stainless steel. There are many drill bit manufacturers, and the more famous domestic ones have flagship stores on JD.com: (Note that there are many types of drill bits, which are not listed here one by one. Find the drill bit that suits you by yourself. It must be suitable for your electric drill connector, the diameter of the hole you want to open, and the hardness.)

2. Non-metallic drill bits:

Sort by hardness: concrete, masonry, plastic, wood. This is just a general classification. In fact, some artificial synthetic materials, such as plastic, are harder than concrete. The rules for selecting drill bits are the same as metal, but non-metallic materials are generally easy to shape, and there are many types of drill bits. Especially wood. Generally speaking, drill bits for metal can be used to make holes in non-metallic materials, but non-metals have their own characteristics. It is recommended to choose drill bits according to the material.

Woodworking drill: (for wood)

The difference between a woodworking drill and a twist drill is that the top of the drill bit is different. The top of the woodworking drill is a triangular needle tip, which is used to fix the center of the hole. The selection of woodworking drills does not need to select the brand of a large manufacturer like metal, and carbon steel of general material is ok. You can choose according to sales volume.

Summary: In fact, there are many types of drill bits. Here we introduce the commonly used drill bits. I hope it can help you understand how to choose the right drill bit according to the material and needs. In my opinion, the drill bit is much more important than the electric drill, but in daily life and work, we often ignore this key point. We are competing with electric drills, and few people compare whose drill bit is better.