Dial Bore Gages - Mitutoyo

Mitutoyo Mechanical Bore Gages, also known as Mechanical Holtests, are precision measuring tools used to measure the diameter of holes, bores, and cylinders. These gages use a mechanical dial or Vernier scale to display the measured value.

The Mitutoyo Mechanical Holtest internal micrometer features three hardened-steel anvils evenly spaced at 120° for true alignment of the axis bore for accurate, easily repeatable measurements. Contact points are coated with Titanium Nitride (TiN)* for added durability and precision. The holtest’s ratchet stop mechanism provides a constant measuring force on the hardened-steel spindle to ensure accurate, even measurements.

• Available in Metric and Inch models
• Optional extension rod allows for measuring deep holes
• Optional setting rings for zero point adjustment are available
• Scale on thimble and sleeve is laser etched for easier reading in all conditions
• Holtests up to 100mm / 4″ diameter measurements supplied in a fitted plastic case
• Holtests over 100mm / 4″ diameter measurements supplied in a wooden case

* Models under 5-6mm / .24-.28″ are carbide.