Spi 34-221-2 Plug Thread Gage 5-40 6H No Go

Product Description

The SPI 34-221-2 is a single-end plug thread gage used to verify that an internal thread does not exceed maximum material condition limits. Classified as a No Go gage, it checks that a tapped hole is not undercut or oversized beyond tolerance. The gage is machined from steel and conforms to the 5-40 thread specification with a 6H tolerance class. It ships without a handle — a Size 0 handle is required for use and must be ordered separately. Inspection personnel and machinists use this tool in quality control and production environments where threaded-hole acceptance criteria must be documented.

This gage is suited for inspection of 5-40 internally threaded components in precision machining, instrument assembly, and light mechanical fabrication. The 6H classification aligns with standard tolerance requirements for general-purpose metric and unified fine-pitch threads in commercial and industrial applications. It is appropriate for both incoming inspection of purchased parts and in-process verification on the production floor.

Key Features

• No Go plug gage confirms internal thread does not exceed maximum material limits
• 5-40 thread size for small-diameter fine-pitch applications
• 6H tolerance class meets ANSI and NIST standards
• Steel construction for durability in production inspection use
• NIST traceability certification included for documentation and calibration records
• Single-end design; requires a Size 0 handle (sold separately)

Compatibility

Designed for use with Size 0 thread gage handles (not included); compatible with standard plug gage handle systems that accept this size class. Intended for inspection of 5-40 internally threaded workpieces conforming to ANSI standards.

Installation Notes

This gage is installed into a compatible Size 0 handle before use — do not attempt to use the gage member without a properly fitted handle. Store the gage in a clean, dry environment and apply a light coat of instrument oil when not in use to prevent corrosion. Periodic recalibration against NIST-traceable references is recommended to maintain measurement integrity. Handle and gage members should be inspected for wear or damage before each use.