For measuring V, American National, Unified, and Unified J series screw threads. These micrometers have a pointed spindle and a double V-anvil, both shaped to contact the screw thread at the pitch diameter. The micrometer reading, therefore, gives the true pitch diameter which equals the outside diameter of the screw minus the depth of one thread. Frames are rigid, one-piece drop forged steel with no-glare satin chrome finish all over. One-piece hardened spindle with threads ground from the solid. Furnished with a fixed (non-rotating) anvil, without ratchet stop or lock nut, and appropriate standards.
