Interesting Work A custom mill cylinder we just built. They like them heavy duty! Piston assembly from an 8″ bore industrial cylinder, completely refurbished with bronze overlay. An 18″ bore cylinder we just finished. About 380 tons push force. We made a new 5 1/2″ rod and reworked the piston. A new Yates industrial cylinder – 24″ bore, 3000 PSI. 1.35 million lbs. of force, 678 tons!