Hydraulic tool holder with coolant jets

A metal working assembly comprising a tool holder having a smooth circular interior bore of fixed diameter, a lathe shaft having one end portion insertable in said interior bore and an opposite end supporting a metal working tool, hydraulically actuated expansion means acting between said lathe shaft end portion and said interior bore to clamp said lathe shaft to said tool holder, and wherein said hydraulically activated expansion means comprises a flanged bushing insertable into said circular bore of said tool holder, said flanged bushing having a coaxial bore, said lathe shaft insertable into said coaxial bore of said bushing;

• and an expandable chamber within said bushing acting when pressurized to clamp said bushing to said tool holder circular bore and to said lathe shaft, and further wherein said tool holder has a flat front surface, said flange of said flanged bushing abutting said flat front surface, said flange being in the form of an arcuate segment, said at least one nozzle being located on said flat front face of said tool holder in the area left open by said arcuate flange segment, at least one cooling fluid spray nozzle for spraying cooling fluid on said working tool;
• and a conduit provided internally of said tool holder forming part of the fluid flow path feeding said at least one nozzle.