Screw Pitch Gages are finely crafted measuring devices used for gauging both internal and external thread pitches on tapped holes, screws and nuts. This set of 22 Screw Pitches includes popular Metric sizes from .35mm to 6.0mm. When not in use, the Gages can be rotated into the tools housing to protect their edges. 22 Metric Screw Pitch Gages. Used for measuring inner and out thread pitches. Includes Metric screw pitches .35mm to 6.0mm. Gages are notched for measuring internal threads. Knurled locknut holds gages in open or closed position. Gages rotate into tool body for protection when not in use.