Spi 14-036-8 Screw Pitch Gage 28 Leaf 4 to 80 Tpi

Product Description

The SPI 14-036-8 is a 28-leaf screw pitch gage used to identify and verify thread pitch on threaded fasteners and machined components. It covers a range of 4 to 80 threads per inch (TPI) and is built for a 60-degree thread angle, which is standard for Unified National thread forms. The leaves are made from steel for durability under shop conditions. A locking mechanism holds the selected leaf in position during measurement. This tool is used by machinists, maintenance technicians, and fabricators who need a fast, reliable way to confirm thread pitch without a thread micrometer.

The 14-036-8 is suited for both external and internal thread identification across a broad TPI range, making it useful in general machining, assembly, repair, and inspection workflows. It works on bolts, studs, nuts, tapped holes, and threaded fittings. The 4 to 80 TPI range covers coarse and fine thread series commonly encountered in inch-based fastener and component work. This gage is a standard hand tool kept in toolboxes and inspection stations in manufacturing, maintenance, and trade environments.

Key Features

• 28 individual leaves cover 4 to 80 TPI in a single tool
• 60-degree thread angle matches Unified National (UN/UNC/UNF) thread form standard
• Identifies both external and internal thread pitch
• Steel construction for wear resistance in shop use
• Locking mechanism secures the selected leaf during measurement
• Inch measurement type for use with standard fastener specifications

Compatibility

Designed for use with inch-series threaded fasteners and components having a 60-degree thread angle, covering external and internal thread forms across the 4 to 80 TPI range.

Installation Notes

No installation is required. Fan the leaves to locate the blade that matches the thread profile of the fastener or hole being checked. Engage the leaf against the threads and verify full contact along the blade edge under adequate lighting. Power down any machinery before measuring threads on installed components. Keep the tool clean and dry to maintain leaf legibility and pivot action.