This article surveys all researches which have conducted on polycrystalline diamond (PCDs) cutting tools, with particular consideration to the characteristics and performance of diamond-metal interface. There has been a revolution in industry over the fifty years or so, due to the usage of diamond in numerous applications, because of the special properties of diamond, joining diamonds to various materials by brazing requires much more precision than traditional brazing. Diamond is frequently utilized in cutting tools and workpieces because of its great hardness and wear resistance. Copper base filler & nickel base filler are the two materials that are most frequently used as brazing fillers in diamond brazing. This review describes the properties of diamond, how it interacts with metals and alloys, how it wets them, what influences these interactions, and how practical aspects of diamond joining is. Additionally, an analysis is done on a number of new brazing alloys, including amorphous Ni-based brazing filler metals.