Vermont Gage 361110020 Threaded Ring Gage 4-40 Unc Class 3A Go

Product Description

The VERMONT GAGE 361110020 is a Go-type threaded ring gage used to verify the maximum material condition of externally threaded fasteners and components. Machined from tool steel, this single-ring gage is designed for 4-40 UNC threads and is classified to Class 3A tolerances, the tightest standard tolerance class for inch-series external threads. A Go gage confirms that a threaded part will assemble correctly within the tolerance envelope. It is a standard inspection tool used by machinists, quality control technicians, and production floor personnel working with fine-pitch unified thread forms.

This gage is suited for inspection of 4-40 UNC externally threaded parts in both production and quality assurance environments. Number 4-40 UNC thread is a fine-pitch, small-diameter thread commonly found in instrument assemblies, electronics enclosures, small mechanical components, and precision hardware. Class 3A classification makes this gage appropriate for close-tolerance applications where fit and function are critical. It is a single-ring design, used independently as part of a Go and No-Go gage set or as a standalone Go verification tool.

Key Features

• Go-type gage confirms correct thread form and maximum material condition on 4-40 UNC external threads
• Class 3A tolerance classification for tight-tolerance thread inspection
• Single-ring design for straightforward pass/fail verification workflows
• Machined from tool steel for wear resistance and dimensional stability
• Manufactured to NIST-traceable standards for confidence in measurement traceability

Compatibility

Designed for inspection of externally threaded components with 4-40 UNC thread form, Class 3A tolerance. Intended for use with standard Go and No-Go gage inspection protocols for unified inch-series external threads.

Installation Notes

Threaded ring gages are used by quality control and machining professionals and require no permanent installation. Handle gages carefully to avoid impact or contamination that could affect dimensional accuracy. Clean the gage and the part being inspected before use to remove chips, oil, or debris. Store in a protective case away from heat sources to maintain calibration integrity.