Original title: Why are there black, white and gold drill bits? What's the difference? Which one is of good quality? ☞ This is the 12159th article posted by Metalworking (mw1950pub) Editor's note Drilling is a very widely used processing method in mechanical processing. The drill bits used in drilling usually have different colors. So what do these different colors portend? Drilling is a very extensive processing method in the manufacturing industry. I believe that the small partners who often work in the front line of drilling will not be unfamiliar with the drill bit. When purchasing drill bits, drill bits of different materials and colors will be available. So what is the difference between different color drill bits? Is there any relationship between color and the quality of drill bits? Which color drill bit is better to buy? 1. Is there any relationship between drill color and quality? First of all, there is no way to distinguish the quality of drill bits simply from the color. There is no direct and inevitable relationship between color and quality. Different color drill bits are mainly different in processing technology. Of course, we can make a general judgment from the color, but at present, poor quality drill bits will also process their own color to achieve the appearance of high-quality drill bits. 2. What is the difference between different color drill bits? High-quality fully ground high-speed steel drill bits are often white. Of course, rolled drill bits can also be white by fine grinding the outer circle. The reason why they are said to be high quality is that besides the material itself, the quality control in the grinding process is quite strict, and the surface of the tool will not be burned. Black is a nitrided drill bit, which is a chemical method to improve the durability of the tool by placing the finished tool in the mixture of ammonia water and water vapor, and after 540-560C degree heat preservation treatment. At present, most of the black drill bits on the market are only black in color (to cover up the burns or black skin on the surface of the tool), but the actual use effect has not been effectively improved. Expand the full text There are 3 processes to produce drill bits, black for rolling, the worst. The white ones are edged and ground. Because unlike rolling, it does not produce high temperature oxidation, so the grain structure of steel is not destroyed, and it is used to drill workpieces with slightly higher hardness. The tawny drill bit, known as the cobalt-containing drill bit in the industry, is the unspoken rule of the drill bit industry. Cobalt-containing diamonds are originally white, produced by grinding, and later atomized into yellow-brown (commonly known as amber), dhd drill bit , which is the best in circulation at present. M35 (Co 5%) also has a golden color, which is called titanium-plated drill, which is divided into decorative plating and industrial plating. Decorative plating has no effect at all, but it is beautiful and golden. Industrial plating is very good, and the hardness can reach HRC78, which is higher than the hardness of cobalt-containing diamond (HRC54 °). 3. Since color is not the criterion for judging the quality of drill bits, So how exactly do you buy a drill bit? Judging from experience, generally speaking, white bits are all ground high-speed steel bits, and the quality should be the best. The gold ones are titanium nitride plated, which are generally either the best or the worst fooling. And the quality of black is also uneven, some are made of poor carbon tool steel, which is easy to anneal and rust, so it is necessary to blacken it. Generally, when buying a drill bit, you can see the trademark on the drill shank and the mark of diameter tolerance. The mark is clear, and the quality of laser or electric corrosion will not be too bad. If the word is molded, if the edge of the word is bulging, the quality of the drill bit is poor, because the bulging outline of the word will cause the clamping accuracy of the drill bit to fail to meet the requirements, while if the edge of the word is clear and well bounded with the cylindrical surface of the bit handle, the quality is good. In addition, it depends on the cutting edge at the tip of the drill bit. The cutting edge of the fully ground drill bit is very good, and the spiral surface meets the requirements, while the quality of the poor quality is very poor at the back corner surface. Disclaimer: If the video, pictures and text used in this article involve copyright issues,Borehole Drill Bits, please inform us at the first time. We will confirm the copyright according to the proof materials you provide and pay the remuneration according to the national standards or delete the content immediately! Disclaimer: If the video, pictures and text used in this article involve copyright issues, please inform us at the first time. We will confirm the copyright according to the proof materials you provide and pay the remuneration according to the national standards or delete the content immediately! Return to Sohu to see more Responsible Editor:. wt-dthtools.com