Piloted Aircraft Stop Countersink Cutters (often called Micro-Stop Cutters, or Microstop Countersinks) are used to make precision countersinks to accept flush-head fasteners and are used throughout the aviation industry. Omega Technologies cutters are precision ground to exact tolerances to insure concentricity.Cutters may be used in any micro-stop ”cage” that accepts 1/4 – 28 threaded shank cutters. Select the pilot diameter that matches the pre-drilled hole, and the body diameter according to the diameter of the fastener head. Metric piloted aircraft stop countersink cutters and other sizes not listed here, can be quoted on request.