Abstract: A center assembly comprising a center and an oil reservoir, the oil reservoir having a leg extending from its lower wall and formed with a bore extending therethrough and with an oil passage having a lower end opened to the bore and an upper end opened in the inner surface of the lower wall of the oil reservoir, the center fitting in the bore and being formed with an oil channel having one end opened in the outer peripheral surface of a cylindrical body portion of the center and in register with the lower end opening of the oil passage in the leg, the oil channel having the other end opened in a conical front end of the center in the vicinity of its extremity. The lubricant in the oil reservoir flows through the oil passage and channel to the front end of the center to lubricate the front end and the inner surface defining the center hole of work.

Abstract: A center for lathes comprises a tubular casing with its interior serving as an oil chamber, a center rod fitting in the casing and having a conical front end projecting from the casing, front bearings and a rear bearing provided between the casing and the center rod, an oil feeding screw portion positioned between the front bearings and the rear bearing and formed on the center rod, and an oil reservoir provided on the casing. Forward and return oil channels extend between the oil reservoir and the oil chamber to permit the whole oil in the reservoir and the chamber to circulate within the center.