Does the color of the drill bit affect the selection of the drill bit

In mechanical processing, hole processing accounts for about 1/5 of its total processing, and drilling accounts for about 30% of the entire hole processing. I believe that the gold powders working in the drilling line will not be unfamiliar with the understanding of drill bits. When purchasing drill bits, there will be drill bits of different materials and colors. So what is the difference between drill bits of different colors? Does the color have anything to do with the quality of the drill bits? Which color drill bit is better to buy?

Does the color of the drill bit have anything to do with the quality?

First of all: it is impossible to distinguish the quality of the drill from the color alone. There is no direct and inevitable relationship between color and quality. Different colors of drills mainly have different processing techniques. Of course, a rough judgment can be made from the color, but the current poorquality drills are also It will process its own color to achieve the appearance of a high-quality drill.

What is the difference between different colored drill bits?

High-quality fully ground high-speed steel drill bits often appear in white. Of course, rolled drill bits can also achieve white color by fine grinding the outer circle. The reason for high quality is not only the material itself, but also the quality control during the grinding process. Quite strict, no burns will appear on the surface of the tool. Black is a nitrided drill bit. It is a chemical method to improve the durability of the tool after placing the finished tool in a mixture of ammonia and water vapor, and after thermal insulation treatment at 540~ 560C°. At present, most of the black drill bits on the market are only black in color (in order to cover up the burn or black skin on the surface of the tool), but the actual use effect has not been effectively improved.

There are 3 processes for producing drill bits, black is rolling, the worst. The white ones are edged and polished. Unlike rolling, high temperature oxidation does not occur, so the grain structure of steel is not damaged, and it is used to drill workpieces with slightly higher hardness. The yellow-brown drill bit is called cobalt-bearing drill in the industry. This is the unspoken rule of this drill bit industry. Cobalt-containing diamonds are originally white, and are produced by grinding. When atomized later, they are made into yellowish brown (generally called amber), which is the best in circulation at present. M35 (Co 5%) also has a golden color. This drill is called titanium-plated drill, which is divided into decorative plating and industrial plating. Decorative plating has no effect at all, it is beautiful and golden. Industrial plating is very good, the hardness can reach HRC78, which is higher than the hardness of cobalt-containing diamonds (HRC54).

How to choose a drill?

Since color is not a criterion for judging the quality of a drill, how to choose a drill?

Judging from experience, generally speaking, the white ones are generally all ground high-speed steel bits, and the quality should be the best. The golden ones are titanium nitride plated, which are generally either the best ones, or the poor ones that fool people. The quality of black is also uneven, and some are made of poor carbon tool steel, which is easy to anneal and easy to rust, so it needs to be blackened.

Generally, when buying a drill, you can see the trademark on the drill shank and the logo of the diameter tolerance. The logo is clear, and the quality of laser or electrical corrosion will not be too bad. If it is a character-molded character, if the edge of the character is bulged, the quality of the drill bit is poor, because the bulging character outline will cause the bit clamping accuracy to fail to meet the requirements, and the edge of the character is clear, very good and the cylindrical surface of the drill shank The junction is of good quality. In addition, it depends on the cutting edge of the drill tip. The edge of the fully ground drill is well opened, and the helical surface meets the requirements, while the quality of the poor quality is very poor at the relief surface.