Abstract: A cutting apparatus comprises an endless chain body comprising a plurality of plate-like flaps connected to each other for angular movement in a common plane. Each flap has an end face on an inner peripheral side of the chain body, and at least a part of the flaps having a cutting device at the end face. The apparatus further comprises a plurality of sprockets supporting the chain body in tension, and defining a common plane of cut effected by the combination of the chain body and the sprockets. The chain body is supported by a rigid backplate, of thickness not greater than the thickness of the flaps. It provides a firm support to the rotating chain body to permit sliding movement of the chain body within the common plane of cut.

Abstract: The object of the present invention is to provide a method for the manufacturing of a cutting material possessing excellent toughness and a high strength. The composition by weight of the Nickel alloy ingot, is chromium (Cr )14-23%, molybdenum (Mo) 14-20%, tungsten (W) 0.2-5%, iron (Fe) 0.2-7%, cobalt (Co) 0.2-2.5% with the remaining portion being made up of Ni and unavoidable impurities. After undergoing a solution heat treatment process, the Ni ingot undergoes plastic working, at a product ratio above 80%, followed by heating at a temperature of 500.degree.-600.degree. C. for longer than 30 minutes. Heating the alloy of the aforementioned composition at the above mentioned temperature promotes the precipitation of an intermetallic compound possessing a hardness greater than 57 on the HRC. The resulting superior cutting material is resistant to corrosion even when exposed to sea water.