The shape of the composite sheet is circular and is inlaid and welded on a cylindrical cutting tool, and the cutting tool is mounted on the drill body to become a PDC drill bit. PDC drill bits are much cheaper than natural diamond drill bits, but they are only suitable for soft to medium-hard formations. PDC drill bits have been developed rapidly after they were successfully manufactured and used in the early 1970s. They can be used with lower weights on bit and higher speeds, high drill footage, and low unit footage cost. In most oilfield projects, diamond polycrystalline composite sheets are inlaid and welded on the scraper, and good results have been obtained.