Q. What do you mean by Ozone Test?

Some research and studies determined that the ozone test was unnecessary as this affects only the surface layer.  In un-stretched rubber, ozone degradation is confined to a thin surface layer, typically 0.5  µ. Ozone cracks develop at right angles to the tensile strain and they degrade rubber's tensile strength and may also initiate fatigue growth that ultimately leads to failure of rubber products.  Because cracks only occur in regions where tensile stresses are induced, they are unable to penetrate very far into objects, which are under compression.  In bearings, the growth of cracks ceases close to the surface because cracks quickly encounter compressive rather than tensile stresses. Therefore, it has been contended that ozone damage is a serious concern in thin-walled products, but not in those bulky products like bearings. Contrarily there is a harmful effect because the manufacturers use anti ozanant waxes to protect against ozone attack.  This viscous layer of wax is responsible for a significant number of serious slipping problems where the bearings 'walked-out' of the support area.