This part of ISO 3597 specifies a method for determining the flexural strength of composite rods of circular cross-section made of roving-reinforced resin. The test may be carried out on “as-moulded” rods, or on rods that have been pretreated by immersion in boiling water (or another medium) for a specified time. The test is intended for inspection and quality control of rovings or for evaluating their suitability for use in a resin system. The results obtained are not intended for the generation of design data.