Spi 10-752-4 Mechanical Hole Micrometer 5 to 6 Inch

Product Description

The SPI 10-752-4 is a mechanical hole micrometer designed for precise internal bore measurement across a 5 to 6 inch range. It features a ratchet stop thimble that applies consistent measuring pressure, helping eliminate operator-to-operator variation during inspection. Solid carbide measuring anvils provide long-term wear resistance in production and metrology environments. With a graduation of 0.0002 inches and an accuracy of 0.0004 inches, this instrument is suited for close-tolerance work where analog readout is preferred over digital. Machinists, tool-and-die makers, and quality control technicians are the primary users.

The SPI 10-752-4 is used in machine shops, manufacturing facilities, and inspection departments for measuring the internal diameter of bores, cylinders, and similar features within the 5 to 6 inch measurement range. Its self-aligning and self-centering three-point contact design allows the instrument to find true diameter without manual alignment effort, reducing the chance of measurement error in repetitive inspection tasks. It is appropriate for both floor-level production inspection and quality lab use.

Key Features

• Measurement range of 5 to 6 inches for mid-to-large bore applications
• 0.0002 inch graduation for fine resolution analog readout
• 0.0004 inch accuracy for close-tolerance bore inspection
• Ratchet stop thimble ensures consistent, repeatable measuring pressure
• Solid carbide measuring anvils resist wear on hardened and abrasive surfaces
• Self-aligning and self-centering three-point contact for accurate diameter location

Compatibility

Designed for use as a standalone mechanical hole micrometer for internal bore measurement in the 5 to 6 inch range. No extension rods or setting rings are included with this unit.

Installation Notes

This instrument is a precision measuring tool and does not require installation in the traditional sense. Handle with care to avoid dropping, which can affect calibration and anvil alignment. Store in the provided case when not in use and keep anvil faces clean and free of chips or coolant residue before measuring. Periodic calibration verification against a certified setting ring or gage block stack is recommended to maintain measurement traceability.