Abstract: A method and apparatus for measuring diameters of holes and countersinks. A tip of a countersink measurement system may be moved to engage a countersink for a hole. A diameter of the countersink may be measured in response to the tip of the countersink measurement system engaging the countersink. A probe may be moved through the tip of the countersink measurement system into a channel for the hole, while the tip is engaged with the countersink. A number of diameters for the channel may be measured as the probe moves in the hole.

Abstract: Apparatus for assembling fasteners includes a fastening wrench operated by a first operator and having interchangeable sockets of different sizes for engaging nuts of different sizes. The nuts are required to be tightened to different torque values on their respective bolts. When the first operator removes a socket from a socket tray in preparation for attaching the socket to the fastening wrench, a signal is sent to a controller which determines the torque value associated with that socket size. When the fastening wrench reaches the specified torque value during the tightening operation, the controller automatically shuts the fastening wrench off. The apparatus also includes a second wrench, operated by a second operator, for engaging the heads of the bolts to prevent them from turning during the tightening process. During the tightening process the second operator may not be in communication with the first operator.