A different measuring range on each gauge makes these sets handy for checking a variety of hole sizes. Each gauge has spring-loaded contacts on the probe, which expand inside holes to measure diameter. Often used for general checks, these sets can make sure that engine cylinders, machine components, and turbines don’t deviate in roundness, which could lead to wear and inefficiency if undetected. Since the gauges reach into holes farther than calipers and inside-hole micrometers, they make it easier to inspect deep holes.

Once the contacts expand inside the hole, turn the screw on the handle to lock the contacts in place. To find the bore diameter, use a micrometer to measure the distance across the contacts.

Versatile enough for general checks, these bore gauges have spring-loaded contacts on the end of their probe to expand inside holes. They’re often used in vehicle repairs and to test parts, such as engine cylinders, for deviations in roundness that could lead to wear. Since they reach father into holes than calipers and inside-hole micrometers, these gauges make it easier to measure a deep hole’s diameter.

Once the contacts expand inside the hole, turn the screw on the handle to lock the contacts in place. To find the bore diameter, use a micrometer to measure the distance across the contacts.

Measure a variety of hole diameters. These sets include gauges that use spring tension to expand the probe’s contacts inside of bores. Each gauge has a different measuring range, so they’re useful for general checks. Use them to test engine cylinders, machine components, and turbines for deviations in roundness that could lead to wear or inefficiency. Designed to reach down into bores, they measure the diameter of deep holes better than calipers and inside-hole micrometers.

Once the contacts expand inside the hole, turn the screw on the handle to lock the contacts in place. To find the bore diameter, use a micrometer to measure the distance across the contacts.