Mitutoyo 511-723-20 Dial Bore Gauge

Technical Overview

High-precision 2-point dial bore gage with a 50-150mm range, 0.001mm resolution, ±2µm accuracy, carbide-tipped contacts, and a heat-insulated hollow grip.

Key Features

Wide internal diameter measurement range from 50 mm to 150 mm
High-sensitivity 2109AB-10 dial indicator with fine 0.001 mm graduation increments
Carbide-tipped contact points and anvils provide outstanding wear resistance and durability
Redesigned hollow-structured handle reduces heat transfer from operator's hand by 50%
Self-centering system via a pendulum centering bridge ensures accurate alignment
Includes a comprehensive set of 11 interchangeable anvils, a 50 mm sub-anvil, and 4 spacers
Rugged protective cover protects the dial indicator during shop-floor operation
Supports optional extension rods for deep-hole measurement capabilities

Technical Specification Matrix

Parameter	Value
Measuring Range	50 - 150 mm
Graduation / Resolution	0.001 mm
Accuracy	±2 µm
Repeatability	0.5 µm
Adjacent Error	1 µm
Probing Depth	150 mm
Measuring Force	5 N or less
Guide Force	10 N or less
Stroke of Contact Point	1.6 mm
Number of Anvils	11 (Includes 50 mm Sub-Anvil)
Number of Spacers / Washers	4 (0.5 mm thick)
Contact Point Material	Carbide
Stem Diameter	8 mm
Dial Indicator Model	2109AB-10
Dial Protection Cover Model	21DZA000
Physical Weight (kg)	0.42
Dimensions L x W x H (cm)	28.2 x 0 x 0

Industrial Applications

1. Automotive Engine Block Cylinder Boring Inspection

Used to inspect the inside diameter of engine cylinders (typically 75–100 mm) during machining or engine rebuild processes. The ±2 µm accuracy and 0.5 µm repeatability of the 511-723-20 allow operators to detect micro-level taper and out-of-roundness deviations that could prevent proper piston ring sealing.

Problem Solved

Prevents engine performance loss and premature piston wear by verifying precise cylinder dimensions without thermal expansion errors from the operator's hand.

cylinder boringtaper inspectionroundness checkingthermal insulationpiston clearance

2. Hydraulic Cylinder Sleeve Quality Control

Measures the inside bore diameters of mid-sized hydraulic cylinder sleeves (50 to 150 mm range) at various depths up to 150 mm. This verification ensures that cylinder inner walls are perfectly cylindrical and within specification before seals and pistons are fitted.

Problem Solved

Avoids fluid bypassing and premature hydraulic seal failure due to out-of-round or hourglass-shaped internal bores.

hydraulic sleeveprobing depthseal tolerancedimensional accuracybore wear

3. Industrial Bearing Housing Bore Inspection

Inspects precision bearing journal housings on rotating machinery prior to press-fit or slip-fit assembly. Because bearing seat clearances are specified within microns, this 0.001 mm resolution instrument checks diameter tolerances to guarantee proper interference fits.

Problem Solved

Prevents bearing misalignment, thermal runaway, or spindle lockups caused by incorrectly sized housing seats.

bearing housingpress-fit verificationjournal inspectionmicron resolutioninterchangeable anvils