Insize 3281-4, SCREW THREAD MICROMETER, 3-4″, 6928640328237

Graduation .001″.
Measures pitch diameter of screw threads.
Non-rotating spindle. Ratchet stop.
Supplied with 60? setting standards (except 0-1″).
Optional accessory: 55?setting standards, measuring tips (pat no. 7381).