Spi 34-220-4 Plug Thread Gage 5-40 6H Single End Go

Product Description

The SPI 34-220-4 is a single-end Go plug thread gage designed to verify internal threads to the 5-40 UNC specification at 6H tolerance class. Machined from steel, this gage gives technicians and machinists a reliable pass/fail check on threaded holes in small fastener applications. The Go member confirms that the thread form, pitch, and minor diameter fall within the acceptable tolerance zone. A NIST-traceable traceability certification is included, making this gage suitable for use in quality-controlled and inspection environments. Handle is not included and must be sourced separately to match the Size 0 handle specification.

This gage is used in precision machining, assembly inspection, and quality assurance settings where 5-40 threaded components must be verified before acceptance. Typical applications include small instrument hardware, electronics enclosures, and light mechanical assemblies that use the 5-40 thread form. It is sized for a Size 0 handle, which is standard for small-diameter thread gages in this range. Metrology technicians, machinists, and quality inspectors are the primary users of this tool.

Key Features

• Go member only — single-end design for dedicated pass verification of 5-40 internal threads
• 6H tolerance class per ANSI standards, suitable for general-purpose precision threading requirements
• Steel construction provides durability and wear resistance in production inspection environments
• NIST-traceable traceability certification included for use in documented quality systems
• Designed for Size 0 handle — handle sold separately, not included
• Meets ANSI and NIST standards for thread gage conformance

Compatibility

Designed as an OEM-style Go plug thread gage for verifying 5-40 UNC internal threads at 6H tolerance class. Compatible with standard Size 0 thread gage handles sold separately.

Installation Notes

A licensed or trained metrology technician or machinist should handle and store thread gages properly to prevent wear or damage to the gage members. Before use, ensure the gage and workpiece threads are clean and free of chips, burrs, or cutting fluid that could affect measurement results. Do not force the Go member through a thread — if resistance is encountered, the thread is out of tolerance or contaminated. Store in a protective case away from sources of impact, moisture, and temperature extremes to maintain calibration integrity.