Patents Assigned to Precision Twist Drill & Machine Co.
  • Method and means of manufacturing a rotary cutting tool
    Patent number: 4383784
    Abstract: The production of rotary cutting tools using very small amounts of premium alloy steel such as tungsten or cobalt as the primary cutting or wearing surface welded to a longer lower grade of tool steel as the secondary wearing or cutting surface.
    Type: Grant
    Filed: October 16, 1981
    Date of Patent: May 17, 1983
    Assignee: Precision Twist Drill & Machine Co.
    Inventor: Richard C. Gulbrandsen