Abstract: A tough cermet made from 20-92 weight % of TiC and/or TiCN, 5-50 weight % of WC and 3-30 weight % of an iron-group metal. This tough cermet has a three phase grain microstructure consisting of a core phase rich in TiC and/or TiCN, an intermediate phase rich in WC and surrounding the core phase, and an outer phase made of (Ti,W)C and/or (Ti,W)CN and surrounding the intermediate phase. Because of this three-phase microstructure, the cermet has high toughness without sacrificing hardness. It is prepared by using WC powder of as fine as less than 3 .mu.m, without taking the course of forming a solid solution of TiC and/or TiCN and WC and pulverizing it.

Abstract: A sleeve assembled in a casting apparatus through which a molten metal is fed into a die cavity, characterized in that at least part of said sleeve on which the molten metal impinges or flows fast under high pressure is made of cemented carbide consisting essentially of a hardening phase of WC, part of which may be substituted by TaC, NbC, TiC, etc., and 10-20 weight % based on the cemented carbide of a binder phase comprising Co, Ni, Cr, and optionally Mo, a weight ratio of Cr+Mo to the binder phase being 0.1-0.2 and a weight ratio of Mo to Cr being up to 3. This sleeve, when assembled in a die-casting apparatus or a low-pressure casting apparatus, enjoys an extremely long life because of its high resistance to oxidation and washing.

Abstract: A milling cutter for cutting the contaminated surface of concrete and used at the time of repairing and dismantling nuclear facilities. The milling cutter is characterized in that guide grooves are provided on the outer surface of a body, with their edges slanted from both sides of the body toward the center thereof, and that cutter chips are located along the stepped edge of each of the guide grooves in such a manner that the cutter chips can be easily detached and that those located along the stepped edges of the adjacent grooves are symmetrical in relation to the center line of the body.