Spi 16 Thread Pitch Diameter Measuring Wire 48 to 3 Tpi

Product Description

The SPI 16 is a 48-piece thread pitch diameter measuring wire set used to accurately measure the pitch diameter of threaded fasteners and tapped holes. Each wire in the set is 3 inches long, and the set covers a range of 48 to 3 TPI for unified inch threads and 0.5 to 6mm pitch for metric threads. Machinists, tool-and-die workers, and quality-control technicians use these wires in conjunction with a micrometer to determine actual pitch diameter, which is critical for verifying thread form and tolerance compliance. The set weighs 0.25 pounds and is sold as a single package of 48 wires.

This measuring wire set is suited for use in precision machining environments, job shops, inspection departments, and manufacturing facilities where both inch and metric threaded components must be verified. The broad TPI and pitch range makes the set practical for general-purpose thread inspection across a wide variety of fastener sizes, from fine-pitch metric threads starting at 0.5mm up through coarse unified threads as low as 3 TPI. It is well suited for benchtop inspection work and can be used alongside standard outside micrometers.

Key Features

• Covers 48 to 3 TPI for unified inch thread inspection
• Covers 0.5 to 6mm pitch for metric thread inspection
• Each wire is 3 inches long for stable micrometer contact
• 48-piece set provides broad coverage in a single kit
• Lightweight at 0.25 pounds for easy bench use and storage

Compatibility

Designed for use with standard outside micrometers for three-wire pitch diameter measurement on unified inch and metric threaded parts within the specified TPI and pitch ranges.

Installation Notes

Thread measuring wires are a metrology tool, not an installed component. Handle wires carefully to avoid nicks or bends that would affect measurement accuracy. Store wires in their case when not in use to prevent damage. Follow established three-wire measurement procedures and apply the appropriate constant for the thread form being measured.