Mechanical Instruments

THREAD MICROMETER

This is a tool that is used to measure the pitch diameter of a screw. This tool looks like a standard micrometer except that the anvils are specially configured to reach into the screw thread groove and touch the pitch diameter of the screw thread. The 
screw thread micrometer does not measure any other aspect of the screw thread. It does not measure the: pitch; threads-per-inch; major diameter; minor diameter; flank angles; lead; helix angle.

Filler Gauge



Tachometer


A tachometer(revolution-counter, Tach,rev-counter,RPM gauge) is an instrument measuring the rotation speed of a shaft or disk, as in a motor or other machine. The device usually displays the revolutions per minute(RPM) on a calibrated analogue dial, but digital displays are increasingly common. The word comes from
GreekΤαχος,tachos, "speed", andmetron, "measure".
This instrument is commonly seen in labs.