Abstract: The thread gauge permits the user to determine the pitch diameter of tapered threads at the intersection of the pitch cone and the end face of the object being measured. A pair of opposed anvils having lines of threads which match the configuration and taper of the threads on the part being measured are brought into meshing engagement with the threads on opposite sides of the part. The anvils are located linearly into their proper positions by stop fingers on the anvils that are brought into abutting engagement with the end face of the part. This places predetermined reference points of the pitch cone of the thread anvils in registration with corresponding points on the end face of the part being measured, resulting in an accurate determination of the pitch diameter at that location. The thread anvils can be arranged for measuring either internal or external threads.

Abstract: A thread gauge which attaches to a vernier caliper to measure the thread pitch diameter of both externally threaded and internally threaded parts. A pair of anvils are externally threaded with threads having the same pitch as those of the threaded part. Each anvil is mounted on a stem having a ball on which the anvil can rotate to properly mate with the parts to which the anvils are applied. The stems are detachably secured to the caliper blades by attachment collars having keyhole openings for receiving the stems and caliper blades. A set screw is used to secure each collar on its caliper blade.

Abstract: A thread gauge which attaches to an inside micrometer to measure the thread pitch diameter of internally threaded parts. A pair of anvils have external threads which match in pitch with the threads of the part. Each anvil has a bore which receives a ball and a slot which receives a stem projecting from the ball. Mounting sleeves connect the stems with the opposite ends of the micrometer. Each anvil can rotate on its ball about the stem axis so that the micrometer can be adjusted to position the anvils against the threaded part. The anvils can also move linearly on the balls to properly align with the threads of the part.