Measuring ID/OD On The Shop Floor

Mahr Federal’s bench-mounted indicator gage is said to provide a handy way to measure ID and OD on the shop floor. Available in both T-plate and V-plate styles and in two sizes, the 36 B ID/OD indicator gage can measure IDs from 0.75″ to 9″ and ODs from 0.25″ to 9.5″. The gage is equipped with a dial indicator, either a Maxum III or µMaxim indicator, and a variety of jaw sets and contacts.

The T-plate configuration gives a diameter reading directly across the diameter (a third contact may be used as a side-step or centralizer), while the V-plate configuration is self-centralizing. Frequently used to inspect parts with odd number lobing conditions, the three “V” jaws measure the distance between the sensitive contact and the chord formed by the two reference contacts. This measurement bears a direct relationship to the diameter, and the compensation is made by a special ratio indicator so the diameter is read directly.

The gage features adjustable contact retraction, which allows for the measurement of grooves and races. Frictionless reed-spring motion transfer facilitates repeatability, and gaging pressure is adjustable from 0 to 35 N/0 to 8 lbs.

The gage can be positioned at any angle from horizontal to vertical. Reversing the top-plates changes the measurement from ID to OD. The indicator is supplied with JW-9 jaws but special spherical contacts are also available in steel and tungsten carbide. Doughnut-shaped contacts as well as ball-and-pie plate contacts are also available.