Mitutoyo 468-278 Digimatic Holtest Inside Micrometer 8-9 In / 0.0001 In with SPC Output

The Mitutoyo 468-278 Digimatic Holtest is a digital three-point internal micrometer designed for precise bore measurement in the 8–9 inch (203.2–228.6 mm) range. It delivers a resolution of 0.0001 in / 0.001 mm and features Mitutoyo's Digimatic SPC data output for seamless integration with statistical process control systems and data collection devices.

Built for demanding shop-floor environments, the Holtest uses a self-centering three-point contact system that automatically aligns to the true diameter of a bore, eliminating the rocking error common with two-point instruments. The integrated Ratchet Stop ensures consistent, repeatable measuring force on every measurement.

Key Features:

• Measurement Range: 8–9 in / 203.2–228.6 mm
• Resolution: 0.0001 in / 0.001 mm
• SPC Output: Digimatic data port for connection to SPC data collectors, displays, and statistical software
• TiN-Coated Measuring Contact Points: Titanium nitride coating provides superior wear resistance, impact durability, and enables measurement to the bottom of blind holes
• Ratchet Stop: Ensures constant, repeatable measuring force for consistent readings
• Large LCD Readout: Easy-to-read digital display for fast, accurate readings in any environment
• Self-Centering Three-Point Contact: Automatically aligns to true bore diameter for reliable, error-free measurements
• Inch/Metric Switchable: Single instrument reads in both in and mm

The Mitutoyo 468-278 is ideal for quality control inspection of large bores in machined components, engine cylinders, hydraulic housings, and industrial manufacturing applications where high-precision inside diameter measurement is required.