Cemented carbide drill is a kind of equipment used in drilling engineering. A drill bit used in core drilling. The steel cylindrical drill body is named after the tungsten carbide inlaid and welded. The shape of the cemented carbide drill cutting tool and the number of inlaid welding on the drill bit, the arrangement method, and the different inlaid welding angles are called the bottom edge, the inner edge and the outer edge to ensure that there is a gap between water flow and powder discharge. The upper part of the bit body is threaded to connect the core pipe, the side part of the bit body is provided with a water groove, and the bottom lip surface is also provided with a nozzle. Both the sink and the nozzle ensure the circulation of the flushing fluid, and achieve the functions of removing rock dust and cooling the drill bit. In order to increase the gap when drilling into clay layers and shale formations, ribs are welded on the inner and outer side walls of the hard alloy drill bit, which is called a ribbed drill bit. Needle-shaped cemented carbide self-grinding drills can be used in hard formations with high abrasiveness. Generally, cemented carbide drill bits can drill into rock formations with grade II to VII; needle-shaped  cemented carbide drill  bits can drill into rocks of grade VI to Ⅷ.

During the production of cemented carbide drill  bits, the main cutting edge of the drill bit will produce many burrs, so the burrs are fine, and the drill bit edge is zigzag under the microscope of a hundred times. If it is not removed, it is easy to produce jump edges during drilling. The phenomenon of block dropping, and then the cutting edge begins to fall off. This gap will aggravate the wear during cutting, which will seriously shorten the service life of the tool. Now there is a perfect way to solve this problem, that is to passivate the drill, the main cutting edge is passivated to form a circular arc shape, reduce the edge of the drill, and can improve the surface quality of the workpiece after drilling.

Passivation treatment is also called strengthening treatment. After the cemented cemented carbide drill  undergoes this process, the front edge of the cemented carbide drill bit will form a very small R arc, which will disperse the cutting resistance and eliminate some fine points on the edge and ligament. Zigzag shape, thereby enhancing the rigidity of the cutting edge.