Mitutoyo 511-716-20 Dial Bore Gauge Set

Technical Overview

2-point metric dial bore gauge set covering 250-400mm range. Features 0.01mm graduation, ±2µm accuracy, 250mm depth, and 50% hand-heat reducing hollow grip.

Key Features

Broad measuring range covering internal diameters from 250 mm to 400 mm
High-accuracy performance with a wide-range accuracy of ±2 µm and repeatability of 0.5 µm
Generous probing depth of 250 mm for measuring deep bore sections
Innovative hollow-structure handle reduces thermal transfer from operator's hand by 50%
Alloy steel anvils with carbide-tipped contact points and anvils for extreme wear resistance
Includes Mitutoyo 2046AB Dial Indicator with 0.01 mm graduation
Protected by a rugged dial gauge protective cover (model 21DZA000)
Supplied with 5 interchangeable anvils, a 75 mm sub-anvil, and 7 interchangeable washers (0.5 mm thick) in a fitted case

Technical Specification Matrix

Parameter	Value
Measuring Range	250 - 400 mm
Graduation	0.01 mm
Accuracy	±2 µm
Repeatability	0.5 µm
Measuring Depth	250 mm
Stroke of Contact Point	1.6 mm
Number of Anvils	5
Sub-Anvil	75 mm
Number of Washers	7 (0.5 mm thickness)
Dial Indicator Model	2046AB
Indicator Protection Cover	21DZA000
Gage Stem Diameter	8 mm
Physical Weight (kg)	0.95
Dimensions L x W x H (cm)	0 x 0 x 0

Industrial Applications

1. Large-Bore Cylinder Liner Ovality Inspection in Marine Propulsion Engines

Large-bore cylinder liners (between 250 and 400 mm in diameter) in commercial marine engines experience continuous thermo-mechanical wear, leading to taper and ovality. Quality assurance technicians use the Mitutoyo 511-716-20 to take multidirectional 2-point comparisons at varying stroke depths up to 250 mm to monitor uniform cylindrical shape.

Problem Solved

Provides the accuracy (±2 µm) and repeatability (0.5 µm) necessary to detect wear patterns and out-of-round conditions before blow-by, high lubricant consumption, or catastrophic piston seizure occurs.

Cylinder Liner OvalityOut-of-Roundness Metrology2-Point Inside DiameterEngine Maintenance MetrologyCylindricity Inspection

2. Geometric Verification of Heavy-Duty Hydraulic Actuator Cylinders

During the manufacturing of massive industrial hydraulic cylinders, the internal bore (250-400 mm) must stay perfectly uniform across its stroke to prevent bypass leakage. Operators utilize the 511-716-20 to measure taper and barrel-shaping inside the cylinder bore down to a 250 mm depth.

Problem Solved

Ensures that high-pressure piston seals maintain dynamic contact pressure. The gauge's self-centering centring bridge easily guides the tool inside the cylinder bore, eliminating user alignment errors in deep bores.

Hydraulic Cylinder QCInternal Diameter UniformityTaper MeasurementSelf-Centering GuideSeal Interface Check

3. Power Plant Turbine Housing Bearing Journal Metrology

High-capacity power turbine bearing housings rely on ultra-precise internal clearances in the 250-400 mm range. Maintenance engineers in hot turbine halls hold the 511-716-20 for prolonged intervals while measuring housing bores to determine alignment and wear profiles.

Problem Solved

Solves measurement inaccuracy caused by operator body heat expanding the tool frame. The hollow, insulated grip reduces hand-to-tool thermal transfer by 50%, maintaining stable sub-micron repeatability under varying ambient temperatures.

Turbine Bearing JournalThermal Expansion DriftBearing Housing QCInsulated Grip MetrologyClearance Verification