Jato Precision has developed the JAL636-PL, a 6500rev/m open-centre pneumatic cylinder with a 36mm through-hole, designed for actuation of 5c collets. The JAL636-PL pneumatic cylinder has low temperature rising to avoid thermal error of the spindle system of CNC lathes. It also largely decreases building cost of the machine since no hydraulic pump, tank and cooler are needed. The cylinder is powered by compressed air, and the temperature rising of the cylinder body is less than 8C when running at 6500rev/m. JAL636-PL comes with compact size and low mass, 162mm in diameter, 144mm in length, and 7.2kg in weight. The pneumatic cylinder is designed to actuate 5C or compatible spring collets whose tapered angle is less than 10deg. The pulling force of the JAL636-PL is enhanced to 935kgf when input air pressure is 7kg/cm2 (100 lb/in2) by embedded elastic springs. This also ensures the work-part will be clamped when the cylinder loses input air pressure suddenly.