Spi 34-216-2 Plug Thread Gage 4-40 6H No Go

Product Description

The SPI 34-216-2 is a single-end No Go plug thread gage designed to verify that internally threaded components do not exceed the maximum material condition for a 4-40 thread form. Manufactured from steel and classified to the 6H tolerance class per ANSI standards, this gage provides a definitive pass/fail check during quality inspection or production threading operations. A No Go gage that enters the threaded feature indicates the thread is out of tolerance. Traceability to NIST is included, making this gage suitable for documented quality control environments. Handle is not included; a Size 0 handle is required separately.

This gage is used in precision machining, inspection, and manufacturing environments where 4-40 UNC threaded holes must be verified against specification. Typical applications include incoming inspection of fastener-receiving components, in-process thread checking on production lines, and final inspection in aerospace, electronics, and mechanical assembly environments. The compact plug design suits small-diameter 4-40 thread forms found in instrument enclosures, electronic assemblies, and light mechanical hardware.

Key Features

• No Go plug verifies thread does not exceed maximum material condition for 4-40 thread
• 6H tolerance class per ANSI standards for precise fit verification
• Steel construction for durability and dimensional stability under repeated use
• NIST traceability certification included for documented QC compliance
• Single-end design; Size 0 handle sold separately
• Meets ANSI and NIST standards

Compatibility

Designed for use with 4-40 UNC internally threaded components requiring 6H class tolerance verification. Requires a Size 0 plug gage handle, not included with this gage.

Installation Notes

Thread gages are inspection tools and do not require installation in a mechanical system. Handle the gage with clean, dry hands or lint-free gloves to prevent corrosion and dimensional contamination. Store in a protective case away from impact, moisture, and temperature extremes to maintain calibration integrity. Do not force the No Go gage into a threaded feature; if it enters, the thread is nonconforming and should be flagged for rejection or rework.