Starrett 50588 Screw Pitch Gage 27 Leaf 2-1/4 to 28 Tpi

Product Description

The STARRETT 50588 is a steel screw pitch gage used to identify and verify thread pitch on fasteners and threaded components. It contains 27 individual leaves, each stamped with a specific thread pitch, covering a range of 2-1/4 to 28 threads per inch (TPI) at a 60-degree thread angle. Technicians fan out the leaves one at a time and match them against a threaded workpiece until the correct pitch is confirmed. This tool is standard equipment for machinists, maintenance mechanics, pipefitters, and field service techs who regularly work with threaded hardware across HVAC, plumbing, and mechanical systems.

This gage is suited for both external and internal thread identification in shop and field environments. It works on bolts, screws, pipe fittings, valve stems, and any other inch-series threaded component within the 2-1/4 to 28 TPI range. The all-steel construction holds up to regular shop use and resists wear on the leaf edges where contact with threads occurs. It is a practical go-to reference tool when thread pitch markings are missing, worn, or unknown.

Key Features

• 27 steel leaves cover a continuous range from 2-1/4 to 28 TPI
• 60-degree thread angle matches standard unified inch thread form
• Works on both external and internal threaded components
• All-steel construction for durability in shop and field conditions
• Compact leaf-style design allows quick pitch identification without additional instruments

Compatibility

Designed for use with inch-series threaded fasteners and components with external or internal threads falling within the 2-1/4 to 28 TPI range and a 60-degree thread angle.

Installation Notes

No installation is required for this measuring tool. Before use, ensure the threaded workpiece is clean and free of debris that could interfere with leaf seating. Fan leaves individually against the thread profile in good lighting to confirm a flush match. Store the gage closed to protect leaf edges from damage between uses.