Starrett 56170 Screw Thread Micrometer 1 to 2 Inches

Product Description

The STARRETT 56170 is a mechanical screw thread micrometer designed for precise measurement of screw thread pitch diameters. It covers a measurement range of 1 to 2 inches and delivers an accuracy of 0.00020 inches, making it a reliable tool for thread inspection work in machining, manufacturing, and maintenance environments. The plain thimble provides a clean, low-friction feel during adjustment, and the satin chrome finish reduces glare under shop lighting. Graduation increments of 0.001 inches allow for consistent, repeatable readings. This micrometer is suited for machinists, toolmakers, and quality control technicians who need dependable thread measurement without digital electronics.

The STARRETT 56170 is used in precision machining shops, tool rooms, and mechanical assembly environments where thread pitch diameter verification is required. It handles screw threads in the 28 to 30 teeth per inch range, making it applicable for a wide variety of standard fastener and thread-form inspection tasks. The included anvil is configured specifically for thread contact geometry. This instrument is appropriate for both production-floor spot checks and bench-level inspection routines in residential, commercial, and industrial maintenance contexts.

Key Features

• Measurement range of 1 to 2 inches with 0.001-inch graduation increments
• Accuracy rated at 0.00020 inches (0.0040 mm)
• Plain thimble design for smooth, consistent spindle adjustment
• Satin chrome finish minimizes glare and resists surface wear
• Configured for 28 to 30 teeth per inch thread profiles
• Includes thread-contact anvil; no digital components for simplified field use

Compatibility

Designed for inspection of external screw threads in the 28 to 30 teeth per inch range, covering a 1 to 2 inch pitch diameter measurement span. Suitable for use with standard inch-series threaded fasteners and components requiring direct pitch diameter measurement.

Installation Notes

This instrument is a handheld precision measuring tool and does not require permanent installation. Before use, clean the anvil and spindle contact faces to remove debris that could affect accuracy. Store the micrometer in its case when not in use and avoid dropping or subjecting it to impact. Calibration should be verified periodically against a known standard in accordance with applicable shop quality procedures.