For twist drill bit, coating has three main functions, the first wear-resistant, second lubrication, third is conducive to smooth chip removal, the main advantage is durable.
The first kind of coating is called “no coating”, which is the natural cutter. The drill bit without coating is the least expensive. It is usually used for processing soft materials such as aluminum alloy and low carbon steel.
The second coating is called “titanium nitride coating”. Titanium nitride is the most common coating material and is not suitable for processing materials with high hardness and high processing temperature.
The third coating is called “titanium carbon nitride coating”. Titanium carbon nitride is developed from titanium nitride and has higher high temperature resistance and wear resistance, usually in purple or blue color.
The fourth kind of coating is called “black oxide coating”. The oxide coating can provide better lubricity than the uncoated twist drill bit, and is better in oxidation resistance and heat resistance. It can improve the service life by more than 50%.
The fifth kind of coating is called aluminum titanium nitride coating, and all the coatings are high temperature resistant, so the twist drill bit can be used in a higher cutting environment, for example, processing super alloys. It is also applicable to the processing of steel and stainless steel. However, due to the element containing aluminum, chemical reaction will occur when processing aluminum, so it is necessary to avoid processing materials containing aluminum.
The application of coating is mainly for steel processing, and the processing of copper and aluminum can be properly chosen without coating. Of course, this is also related to the habits of personal use. The high speed steel twist drill bit is recommended to use yellow titanium, while the hard alloy twist drill material is recommended to use purple titanium or steel coating.
Post time: Mar-18-2022