Fowler 52-275-001-1 Mechanical Inside Micrometer

Product Description

The FOWLER 52-275-001-1 is a mechanical inside micrometer designed for precise internal bore and hole measurements. It features a ratchet stop thimble that delivers consistent measuring pressure, reducing operator-to-operator variation. The measuring faces are solid carbide for long-term wear resistance. Graduation is 0.001 inches with an accuracy of 0.0002 inches, meeting Federal Accuracy Specifications. The satin chrome finish reduces glare during use. This instrument is used by machinists, toolmakers, and precision measurement technicians who require reliable inside dimensional verification in shop or field environments.

The 52-275-001-1 covers a maximum measurement range of 1.2 inches, making it suited for small-bore work including bushings, bores, and cylindrical features in that range. The included setting ring diameter is 0.2 inches, allowing the user to zero and verify the instrument before measurement. This micrometer is a fit for machine shops, quality control departments, and maintenance environments where internal dimensions must be verified to tight tolerances. No digital counter is included, keeping the design straightforward and durable.

Key Features

• Ratchet stop thimble provides repeatable, consistent measuring pressure
• Solid carbide measuring faces resist wear during high-frequency use
• 0.001 inch graduation with 0.0002 inch accuracy per Federal Accuracy Specifications
• Satin chrome finish minimizes glare in bright shop lighting
• Hardened and ground spindle threads for long-term precision and thread integrity
• Includes carrying case, setting ring, and spanner wrench for complete out-of-box use

Compatibility

Designed as a standalone mechanical inside micrometer for internal measurement applications within a 1.2 inch maximum range. No extension rods or additional contact points are included, and the instrument is intended for direct use without supplemental components beyond the included accessories.

Installation Notes

This instrument is used by machinists, quality control technicians, and precision tradespeople and requires no installation in the traditional sense. Before first use, verify zero with the included setting ring and adjust using the spanner wrench as needed. Store in the included case when not in use to protect the carbide measuring faces and maintain calibration. Do not force the thimble past its ratchet stop, as overtightening can affect accuracy.