6-8mm 0.24-0.31" Three Point Internal Bore Micrometer - 3227 Series (Insize)

The Insize 3227 Internal 3-Point Bore Micrometer is a precision instrument designed for measuring inside diameters of bore holes and cylindrical interiors. It’s ideal for engineers, machinists, quality-control technicians, and hobbyists who need accurate bore measurements with repeatable results.

This micrometer uses a three-point contact head to evenly align with the bore, helping you obtain true diameter readings with less eccentricity. It features a ratchet stop to ensure consistent measuring pressure and carbide measuring faces for excellent wear resistance, delivering reliable performance over many measurements.

• Three-point internal contact for true bore readings: Ensures stable, repeatable measurements across a range of bore sizes by distributing contact pressure evenly inside the hole.
• Wear‑resistant carbide faces with ratchet stop: Prolongs tip life and provides controlled, uniform force for consistent results every time.
• Wide range with included accessories: Measuring range up to 300 mm, 0.001 mm graduation, plus a setting ring and extension rods for deep or hard-to-reach bores.

Designed for demanding workshop environments, the 3227 delivers dependable internal measurements with minimal drift. Its robust build and precise graduations help streamline inspection workflows, reduce rework, and support confidence in part tolerances from small to large bore diameters.