1.1 This part of ISO 899 specifies a method for determining the flexural creep of plastics in the form of standard test specimens under specified conditions such as those of pre-treatment, temperature and humidity. It applies only to a simple freely supported beam loaded at mid-span (three-point-loading test). 1.2 The method is suitable for use with rigid and semi-rigid non-reinforced, filled and fibre-reinforced plastics materials (see ISO 472 for definitions) test specimens moulded directly or machined from sheets or moulded articles. Note The method may be unsuitable for certain fibre-reinforced materials due to differences in fibre orientation. 1.3 The method is intended to provide data for engineering-design, research and development purposes. Data for engineering-design purposes requires the use of a deflectometer to measure the deflection of the specimen. 1.4 The method may not be suitable for determining the flexural creep of rigid cellular plastics (attention is drawn in this respect to ISO 1209-1, Cellular plastics, rigid Flexural tests Part 1: Bending test, and ISO 1209-2, Cellular plastics, rigid Flexural tests Part 2: Determination of flexural properties).