PURPOSE: To obtain a non-magnetic or weak-magnetic diamond sintered compact with low magnetic susceptibility by providing a sintered compact which is composed essentially of diamond having specified grain size and in which binding phase is composed of metallic components containing ferromagnetic iron- group metals and weak-magnetic metals in specific proportions.

CONSTITUTION: In a high hardness sintered compact containing ≥50vol.% diamond having 0.1-100μm grain size, its binding phase is essentially composed of iron-group metals. This binding phase is formed by allowing 1-50% of weak- magnetic metallic components having ≤5×10-6 (eum/g) magnetic susceptibility, such as Cr, V, Cu, Si, Zn, Al, Mo, and W, to form a solid solution in ferromagnetic irongroup metals, such as Ni, Co, and Fe and performing alloying. By the above procedure, the magnetic moment of the diamond sintered compact composed essentially of iron-group metals is reduced by ≥80%, and magnetic susceptibility is regulated to ≤3% of that of Fe. This sintered compact is obtained by mixing binding phase metal component, finer-grained than a diamond powder as a principal component, with this diamond powder and then sintering the resulting mixture under the diamond stability region.