ISO 4666-3:2016规定了用于测定硫化橡胶的温升和耐疲劳性的恒定应变幅度的挠曲仪试验。指定的屈挠仪称为Goodrich屈挠仪，但可以使用任何其他具有同等性能的仪器。 ISO 4666-3:2016给出了进行测量的指导，这些测量可以预测在使用中受到动态挠曲的成品（如轮胎、轴承、支架、V带和电缆滑轮插入环）中橡胶的耐久性。然而，由于使用条件的广泛差异，无法假设本文件各部分所述的加速试验与使用性能之间存在简单的相关性。 对于硬度大于85 IRHD的橡胶，不建议使用该方法。

ISO 4666-3:2016 specifies the flexometer test with constant-strain amplitude for the determination of the temperature rise and resistance to fatigue of vulcanized rubber. The flexometer specified is known as the Goodrich flexometer, but any other apparatus giving equivalent performance can be used. ISO 4666-3:2016 gives directions for carrying out measurements which make possible predictions regarding the durability of rubbers in finished articles subject to dynamic flexing in service, such as tyres, bearings, supports, V-belts, and cable-pulley insert rings. However, owing to the wide variations in service conditions, no simple correlation between the accelerated tests described in the various parts of this document and service performance can be assumed. The method is not recommended for rubber having a hardness greater than 85 IRHD.