This International Standard specifies a method for the determination of in-plane shear strength of continuous-fibre-reinforced ceramic composites at ambient temperature by the Iosipescu test. Methods for test piece fabrication, testing modes and rates (load rate or displacement rate), data collection, and reporting procedures are addressed. This International Standard applies primarily to advanced ceramic or glass-matrix composites with continuous-fibre reinforcement having uni-directional (1-D), bi-directional (2-D) or 3-D fibre architecture. This test method does not address composites with discontinuous-fibre-reinforced, whisker-reinforced or particulate-reinforced ceramics. NOTE 1 Values expressed in this International Standard are in accordance with the International System of Units (SI). NOTE 2 This International Standard is based on ASTM C1292.