Mitutoyo 511-722-20 Dial Bore Gauge

Technical Overview

High-precision 35-60mm internal diameter measuring instrument featuring 0.001mm graduation, ±2µm accuracy, carbide-tipped contact points, and 150mm depth.

Key Features

Self-centering centring bridge ensures automatic, reliable alignment inside the bore.
Hollow-structured grip reduces operator hand heat transfer by 50% for superior thermal measurement stability.
Carbide-tipped contact points and anvils ensure exceptional wear resistance and longevity.
Supplied with 6 interchangeable anvils and 4 spacers for versatile and accurate range adjustment.
Comes with a 2109AB-10 dial indicator and a rugged protective cover to prevent dust and impact damage.
Provides high-accuracy internal measurements with 0.5 µm repeatability and ±2 µm wide-range accuracy.

Technical Specification Matrix

Parameter	Value
Measuring Range	35 - 60 mm
Graduation	0.001 mm
Wide-range Accuracy	2 µm
Repeatability	0.5 µm
Adjacent Error	1 µm
Probing Depth	150 mm
Measuring Force	4N or less
Guide Force	6N or less
Stroke of Contact Point	1.2 mm
Gage Stem Diameter	8 mm
Dial Indicator Model	2109AB-10
Contact Point Material	Carbide-tipped
Physical Weight (kg)	0.4
Dimensions L x W x H (cm)	28.2 x 5.7 x 3.5

Industrial Applications

1. Automotive Engine Cylinder Reboring Quality Control

Measuring engine block cylinder bores (typically within the 35–60 mm range for smaller engines, motorcycles, or auxiliary pumps) to check for taper, out-of-roundness, and wear before and after reboring/honing.

Problem Solved

Mechanics must ensure that the cylinder walls are perfectly circular and straight to prevent blow-by and oil consumption. The 511-722-20 solves this with its 0.5 µm repeatability and 2-point contact system, detecting minimal geometry anomalies.

Cylinder BoreOut-of-roundnessTaper MeasurementHoning MetrologyInternal Diameter

2. Precision Hydraulic Cylinder Sleeve Inspection

Quality assurance of small-bore hydraulic cylinder sleeves (inner diameter 35–60 mm) to verify internal tolerances before installing seals and pistons.

Problem Solved

Microscopic taper or ovality in hydraulic cylinders causes fluid bypass and seal degradation. The 150 mm probing depth and 1.2 mm plunger stroke allow deep inspection into the cylinder to confirm uniform diameter, preventing hydraulic pressure drop.

Hydraulic SleeveSeal Seat VerificationOvality DetectionProbing DepthMicrometer Tolerance

3. Precision Bearing Journal Alignment & Sizing

Checking inside diameters of bearing housings and journals in turbine or transmission systems where high-tolerance press fits are required.

Problem Solved

For high-speed aerospace bearings, a discrepancy of more than a few micrometers in housing diameter leads to premature bearing failure. The gage's ±2 µm accuracy and 0.001 mm graduation allow operators to measure press-fit bores with extreme confidence.

Bearing JournalPress-Fit ToleranceInternal Diameter MetrologyClose-Tolerance MachiningThermal Stability Grip