Screw pitch gauges
The counters are a measuring instrument to determine the pitch of a thread. It is also called lamella caliber because it consists of a series of thin metal sheets on each of which is stamped the pitch. They are called simple if they include the steps of a single type of thread, and two include two, for example metric on one side and imperial on the other. With some it is possible to stop the tabs in the easiest position by tightening the locking screw. It is used to perform fast measurements when not using high precision or thread profile knowledge and is especially useful for determining which male or female thread to use to thread a piece related to another, or to choose the die or screw to be coupled to the counterpart. In other cases, it is advisable to point to the threaded, nut-groove and screw threaded gauges, which can determine both the thread profile and the pitch. Specifically for the measurement of screws with metric pitch, the counters are also called "passimeter".