Finally, the 7% relates to the material composition and the durability of the seals. Oil seals are typically constructed from various compounds, including elastomers and polyurethane, each tailored for specific environmental conditions. A 7% threshold can indicate the percentage of material degradation that is acceptable over a defined lifespan. High-quality seals are engineered to endure extreme pressures and environmental challenges, maintaining their integrity even as their material composition undergoes wear.