The best three-point bore gauge depends on the hole diameter you need to measure. These iGaging digital inside micrometers cover different size ranges, offer inch and metric readings, and use carbide measuring surfaces. The 0.65–0.80-inch model suits smaller bores, while the 3.5–4.0-inch model is for larger openings. A two-point dial bore gauge is also included as a different-style alternative for users who need a broader range and want to check bore geometry.
| Product | Best for | Measurement range |
|---|---|---|
| iGaging 0.65–0.80-inch | Small bores | 0.65–0.80 in / 16–20 mm |
| iGaging 0.80–1.00-inch | Small-to-medium bores | 0.80–1.00 in / 20–25 mm |
| iGaging 3.00–3.50-inch | Large bores | 3.00–3.50 in / 75–88 mm |
| iGaging 3.5–4.0-inch | Larger bores | 3.5–4.0 in / 87–100 mm |
| BOBOVAV dial bore gauge | Broad-range bore checks | 2–6 in / 50–160 mm |
iGaging 0.65–0.80-Inch Three-Point Bore Gauge
This digital inside micrometer is best for buyers measuring bores from 0.65 to 0.80 inches, or 16 to 20 mm. Its listed resolution is 0.00005 inch (0.001 mm), and its stated accuracy is 0.00016 inch. Carbide measuring surfaces are included, and the contact points are designed to reach near the bottom of a blind hole.
Choose this model when the target diameter falls within its compact range and fine-resolution digital readings are useful. Its range is narrow, so it is not the right choice for holes smaller or larger than the stated limits.
iGaging 0.80–1.00-Inch Three-Point Bore Gauge
This model is best for inside measurements from 0.80 to 1.00 inch (20 to 25 mm). It provides inch and metric readings with a listed resolution of 0.00005 inch (0.001 mm) and stated accuracy of 0.00016 inch. It also has carbide measuring surfaces and contact points designed for measurements close to the bottom of blind holes.
It is a better fit than the smaller iGaging gauge when the workpiece bore is closer to one inch. The measuring range is limited to 0.80–1.00 inch, so confirm the hole size before choosing it.
iGaging 3.00–3.50-Inch Three-Point Bore Gauge
Best for larger bores measuring 3.00–3.50 inches (75–88 mm), this digital gauge has a listed resolution of 0.00005 inch (0.001 mm) and stated accuracy of 0.00020 inch. Its carbide measuring surfaces and contact-point design support measurements near the bottom of a blind hole.
Choose this gauge if your required diameter is within its large-bore range and you want inch or metric readings. It cannot cover the full range of larger openings; the 3.5–4.0-inch option is more appropriate above 3.50 inches.
iGaging 3.5–4.0-Inch Three-Point Bore Gauge
This inside hole micrometer is best for bores from 3.5 to 4.0 inches (87–100 mm). It offers a listed resolution of 0.00005 inch (0.001 mm), stated accuracy of 0.00020 inch, carbide measuring surfaces, and contact points designed to measure near the bottom of blind holes.
It is the larger-range choice compared with the 3.00–3.50-inch iGaging model. Select it for work within its stated diameter limits; it does not replace a gauge sized for smaller holes.
BOBOVAV 2–6-Inch Dial Bore Gauge Set
This set is best for buyers who need a wider 2–6-inch (50–160 mm) range and want to assess bore geometry. It uses a two-point contact design, not a three-point measuring system, and the listing describes it as suitable for detecting ovality and taper. It includes 12 anvils, a self-centering design, an insulated handle, and adjustable heads. The stated accuracy is 0.0005 inch (0.01 mm), and the listed depth capability is up to 6 inches.
Choose it as a broad-range alternative, not as a direct three-point substitute. Its stated accuracy is less fine than the iGaging models’ listed figures, and its two-point design may not match a requirement specifically calling for three-point measurement.
Buying Guide: How to Choose a Three-Point Bore Gauge
What diameter range do you need?
Match the gauge’s stated range to the bore being measured. The iGaging options here cover separate bands from 0.65 to 1.00 inch and 3.00 to 4.00 inches. Their ranges do not form one continuous span, so do not assume one model measures every diameter between the listed endpoints.
Does resolution mean accuracy?
No. Resolution describes the smallest displayed increment, while accuracy describes how close a measurement is stated to be to the true value. Compare both figures when selecting a tool. The listed iGaging gauges have 0.00005-inch resolution; their stated accuracy differs by size range.
Will you measure a blind hole?
The iGaging product descriptions say their contact points are designed to allow measurements near the bottom of a blind hole. Consider access and hole depth for your specific work, and verify that the gauge can reach the required measuring location.
Do you need three-point or two-point contact?
Choose a three-point gauge when that contact design is a requirement. The BOBOVAV set uses two-point contact and is described as supporting checks for ovality and taper. It is a different approach and should not be labeled a three-point bore gauge.
Frequently Asked Questions
What is a three-point bore gauge used for?
A three-point bore gauge measures the inside diameter of a hole. Select a model whose specified diameter range covers the bore you need to check.
Which listed gauge measures the smallest holes?
The iGaging 0.65–0.80-inch model covers the smallest range in this selection, from 16 to 20 mm.
Are all the listed products three-point gauges?
No. The four iGaging inside hole micrometers are identified as three-point bore gauges. The BOBOVAV set is explicitly described as a two-point dial bore gauge.
Can these gauges measure near the bottom of a blind hole?
The iGaging descriptions say their contact points are designed to permit measurements near the bottom of a blind hole. Confirm that the tool’s reach suits the particular hole.
What should I compare before buying?
Check the measurement range, stated accuracy, resolution, contact design, and access to the measurement location. These details determine whether a gauge suits the bore and measurement task.