Measure bore diameter directly. These gauges give you the actual diameter, unlike a dial bore gauge, which only shows the variation from a set measurement. An LCD display makes the diameter easy to read. They measure deeper into smaller holes than inside hole micrometers. To test holes of different sizes, swap among the included anvils. Each anvil has two contact points that detect issues with roundness and taper and a flat bottom for stability in blind holes. For repeatable go and no-go tests, set upper and lower tolerances. A bar indicator on the display shows whether your measurement is within bounds, making test results quick to check.

An SPC data output allows you to connect these gauges to a computer or data processor to analyze data and monitor measurements in real time. A zero-set button lets you start measuring at any point. All have zero-position memory, also known as absolute (ABS) positioning, which retains the measuring position when the gauge is turned off. These gauges have alarms to warn you about various issues, including a low battery and setting errors.

Extension rods (sold separately) lengthen the stem of your gauge to reach farther into deep bores.

Gauge blocks (sold separately) come in eight different metric sizes for calibrating your bore gauge.

Data cables (sold separately) connect your gauge to your PC to send data.

Check the diameter of holes with the pull of a trigger. These sets have everything you need for one-handed measurements—a pistol-grip gauge, a head, setting rings, and a stand. This means you can reach holes at awkward angles, such as overhead. The pistol grip also gives you precise control using just your fingertips instead of your whole hand. Unlike dial bore gauges, you don’t need to set a baseline measurement before use. Rotate the LCD display up to 330° to read results at the angle you need. Rated IP54, the gauge withstands dust and splashing water.

For better accuracy, the head has a self-centering probe with three contact points instead of the usual two. The extra contact point makes it easier to sense issues with roundness, a common check in quality control tests. Zero-position memory, also known as absolute (ABS) positioning, retains the measuring position when the gauge is turned off. Connect the gauge to your computer via Bluetooth or the SPC data output to monitor and analyze data in real time.

Use the included setting rings to calibrate your gauge. They come with a calibration certificate traceable to NIST that states they've passed a test for accuracy.

Measure hole diameter in dirty machine shops and the outdoors with the pull of a trigger. Rated IP67, the bore gauge in these sets is protected from dust and temporary submersion in water. Sets include everything you need to measure—a pistol-grip gauge, heads of different measuring ranges, and setting rings. Thanks to its pistol grip, you can take measurements with one hand and reach into awkward angles, such as those overhead. The pistol grip also gives you precise control using just your fingertips instead of your whole hand. The LCD display directly shows the measured diameter, so you don’t need to set a baseline like you do with a dial bore gauge.

Instead of the standard two contact points, each head in these sets has three to center the probe in holes. This improves accuracy for detecting out-of-roundness, a common check for quality control. Connect the gauge to your computer, smartphone, or other device via Bluetooth or the SPC data output to monitor and analyze data in real time.

Use the included setting rings to calibrate your gauge.

Check the diameter of holes with the pull of a trigger. These Starrett sets have everything you need for one-handed measurements—a pistol-grip gauge, heads for varying diameters, and setting rings. Thanks to its pistol grip, you can reach the gauge into awkward spots, such as those overhead. The pistol grip also gives you precise control using just your fingertips instead of your whole hand. Unlike dial bore gauges, you can measure right away, no baseline measurement required. You can even set upper and lower tolerances for quick go/no-go tests. The LCD display has lights and arrows to show if the hole falls within your set tolerance. Rotate the display to read results at the angle you need.

Since the gauge has three contact points, it’s more accurate than a typical bore gauge with two contact points. The probe centers itself, so it’s easier to detect issues with roundness, a common check in quality control tests. To stay accurate, the gauge has alarms to warn you about problems that could skew readings, such as a low battery, a contaminated probe, and test setting errors. Use the included setting rings to calibrate your gauge.

With a zero-set button, you can start measuring at any point. Zero-position memory, also known as absolute (ABS) positioning, retains the measuring position when the gauge is off. Connect the gauge to your computer, smartphone, or other device via Bluetooth or the SPC data output to monitor and analyze data in real time.

Test a variety of tight slots and holes in precision parts, such as electronics. These sets include a gauge with an LCD screen, an array of small head sizes, and setting rings. Unlike analog gauges, you don’t need a micrometer to find the diameter. Slide the full-ball probe into the hole and the diameter will show up directly on the screen, helping you detect issues with roundness. Since the probe makes 360° contact, it’s easier to center in small spots than anvils or spring-loaded contacts. It’s also less likely to tilt within a bore than a half-ball probe, which helps avoid skewed measurements. All sets come with a calibration certificate traceable to UKAS, which includes the test measurements that confirm accuracy. Choose a set with a wider measuring range to complete more measurement tasks using less tools.

The zero-set button allows you to start measuring at any point. Zero-position memory, also known as absolute (ABS) positioning, retains the gauge’s measuring position even when turned off. An SPC data output lets you connect these gauges to a computer or data processor to analyze data and monitor measurements in real time.

Use the settings rings to calibrate your gauge.

USB data cables (sold separately) connect the gauge directly to your PC.

Whether a chamfered edge is in a screw hole or on the end of a rotary shaft, these gauges find its diameter. Use them to confirm the tolerance of edges after milling, drilling, and reaming. They measure chamfers on the inside or outside diameter of your bore. As you trace the probe of these gauges along an edge, an internal sensor records the distance and angle. The calculated diameter displays on the LCD screen for quick readings. All have SPC data output to transfer information to your computer or data processor—you don’t even need any cables.

Choose a gauge with an angle that is greater than or equal to the chamfer angle you are trying to measure.

For technical drawings and 3-D models, click on a part number.

Measure diameters, angles, and other complex geometries—like an optical comparator—but without all the training. These gauges have an easy-to-use touch screen that guides you through taking measurements step-by-step. Extremely precise, they measure in the smallest increments of any height gauge in our offering, and they’re also our most accurate. Use them in machining and toolmaking to mark material before cutting it. To fly through big batches of work, program up to 50 types of repeated measurements.

From calibration reminders to calculation error alarms, these gauges have functions to make sure they give you accurate and consistent readings. Upon startup, they walk you through a scale check to detect traces of contamination that would cause errors. The air bearing system helps the slider glide smoothly up and down yet holds its spot steady when it’s time to measure. Rotate the screen to read it at the angle you need. Zero-position memory, also known as absolute (ABS) positioning, retains the measuring position even when the gauge is turned off.

With up to two months of storage to record actions and measurements, these gauges create an archive you can look through and identify trends. Connect them via Bluetooth to your phone, tablet, or other devices to remotely monitor and analyze data in real time. Otherwise, use the SPC data output to connect to a computer or data processor. To send data right into programs such as Excel, use a USB cord or RS-232 cable (both not included).