Mitutoyo 511-706 Bore Gauge

Technical Overview

Precision 250-400mm standard mechanical bore gauge with carbide-tipped contacts, 250mm probing depth, and a thermal-insulated grip. Indicator not included.

Key Features

Wide measuring range of 250 mm to 400 mm, ideal for large bore inspections.
Hollow-structured, thermal-insulated grip reduces operator hand heat transfer by 50% to maintain stability during prolonged use.
Carbide-tipped contact points and anvils ensure high durability, abrasion, and wear resistance.
Pendulum-guide self-centering system facilitates fast, easy, and highly repeatable alignments.
Two-point contact mechanism effectively checks for dimensional anomalies like out-of-roundness and taper.
Standard 250 mm probing depth (length below the grip) allows for deep bore evaluations.
Supplied with 5 interchangeable anvils (including one 75 mm sub-anvil) and 7 spacers for incremental size adjustments.

Technical Specification Matrix

Parameter	Value
Measuring Range	250 to 400 mm
Accuracy	2 µm
Repeatability	0.5 µm
Adjacent Error	1 µm
Probing Depth	250 mm
Measuring Force	6 N or less
Guide Force	15 N or less
Stroke of Contact Point	1.6 mm
Stem Diameter	8 mm
Contact Point Material	Carbide
Anvils Included	5 (including one 75 mm sub-anvil)
Spacers Included	7
Physical Weight (kg)	0.78
Dimensions L x W x H (cm)	40 x 1.5 x 0

Industrial Applications

1. Automotive and Marine Engine Cylinder Liner Wear Inspection

Checking for out-of-roundness and taper on large engine cylinder bores with diameters between 250 mm and 400 mm. The 2-point contact system and 0.5 µm repeatability allow quality control technicians to accurately map internal wear down to a 250 mm probing depth.

Problem Solved

Identifies localized cylinder liner taper and ovality caused by piston friction and thermal stress, preventing premature compression loss or engine blow-by.

Cylinder Liner InspectionOvality Detection2-Point MeasurementEngine RebuildingCarbide Contacts

2. Industrial Hydraulic Cylinder Barrel Quality Control

Measuring the internal diameter of high-pressure hydraulic cylinder barrels during honing or maintenance. The gauge's 2 µm accuracy guarantees that the internal bore complies with strict tolerances essential for proper piston seal pressure retention.

Problem Solved

Ensures honed bores meet tight inner diameter tolerances, avoiding oil bypass and rapid seal degradation inside high-tonnage hydraulic cylinders.

Hydraulic Cylinder HoneInside Diameter ToleranceSeal Clearance VerificationBore Metrology

3. Turbine and Heavy Machinery Bearing Housing Calibration

Verifying large bearing seat diameters in housings for power generators, gearboxes, or wind turbines. Using the 250-400 mm span with sub-anvils, the gauge detects micro-deviations before heavy interference-fit bearings are permanently pressed in.

Problem Solved

Prevents catastrophic bearing housing misalignment or excessive press-fit tension, minimizing heat generation and rotational friction during machine operation.

Bearing Seat AlignmentInterference FitLarge Bore MetrologyThermal-Insulated Grip