... , 52200, 52300, 52400, 53200, 53300, 53400, 54200, 54300, 54400 series standard types and 511/500 512/500 510/500 593/500 ... /630 511/670 510/670 572/710 592/710 series non-standard series.2. Material: GCr153. Application: Oil drilling machines, screw shaft ... Certificate of Origin3. High precision, long life, low noise, high-end technology, low vibration and conform to the export standard4. Package ...