Technical features: 1. Hydraulic / pneumatic cylinder is built-in. No need for extra cylinders. 2. Aluminum alloy chuck body, light-weighted, good heat dispensation. 3. Clamping precision: 0.03-0.05mm 4. Allows non-stop operation when loading parts. 5. Simple structure, high efficiency, low cost, convenient installation. 6. Widely applied to convert manual lathe into powered ones. 7. Widely applied to build special purpose machines. 8. Do not spray cutting fluid to the chuck directly. 9. The Besides O.D. chucking, customer can easily convert a JA7-44/JH7-44 rotary power chuck into a I.D. expanding chuck by installing an expanding kit including a push-nut, a mandrel, and a expading sleeve. 10. The expanding sleeve is designed and made according to customer's requirement.