On the Failure of Cemented Carbide Tool Observed by Cutting Chilled Cast Iron. Keiji OKUSHIMA, Shukichi NAGATOMI & Kitao OKUSA. Chilled cast iron is one of the materials of the worst machinability, and there are often some difficulties in cutting. We observed the tool failures and how they change according with the time by using twelve kinds of cemented carbide tools. Examining the data, we found out the most preferable type of failure was the combination of the following three basic types of

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... ol failure, (1) rectangle flank wear type by chipping, (2) crater type without land between crater and the cutting edge, and (3) the round type of nose wear. Gradual progression of these tool failures of nose wear which is often found in the nose part is best. Then when this type of failure is measured and expressed as V'B, it is desirable that V'B-time graph is parallel to that of VB(the mean flank wear land). If cutting condition is too severe and cemented carbide consists of coarse WC grains, the tools will be fractured very soon.