PP Plastic Ball Bearing Deep Groove Glass Balls Bearings Polypropylene 608-6006. With a density of only 0.90-"0.91G/CM3, it is one of the lightest varieties of all plastics. Particularly stable to water, water absorption in water is only 0.01%, molecular weight is about 80,000 - 150,000 Formability Good formability, but due to large shrinkage (1% to 2.5%).
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