PURPOSE: To cut hard material such as marble properly by heating diamond particle pellets at a temperature suitable to form some metal carbide from diamond particles wherein a carbide-forming metal is liquefied.

CONSTITUTION: Abrasive particles of diamond to make pellets 14 finally sintered to make a saw blade segment 16 are provided with a dual coating. The inner coating consists of at least 20 wt.% metal carbide of nickel or the like, and the continuous outer coating consists of at least 20 wt.% sintered metal such as cobalt having a sintering temperature that is at least about 50°C lower than the melting point of the inner metal. After the sintering of the outer metal at the sintering temperature, the inner metal is liquefied at a higher temperature to form carbide thereof. The outer sintered metal coating helps to check any loss of the inner metal liquefied and thus to keep the pellets 14 spherical.