Spi 34-304-6 Plug Thread Gage 5/8-11 6H Single End Go

Product Description

The SPI 34-304-6 is a single-end Go plug thread gage machined from steel and designed to verify the minimum material condition of internal 5/8-11 UNC threads to 6H tolerance class. It is used to confirm that a tapped hole accepts a mating fastener within the allowable thread tolerance range. When the Go member passes through the threaded hole, the thread form, pitch diameter, and lead fall within specification. This gage is a standard inspection tool used by machinists, quality technicians, and tool-room personnel working to ANSI thread standards with NIST traceability certification included.

The 34-304-6 is suited for production and inspection environments where 5/8-11 UNC internal threads must be verified against 6H class tolerances. Typical applications include incoming inspection of machined components, in-process thread verification on CNC and manual machining centers, and final quality control checks in manufacturing and fabrication shops. The gage accepts a Size 3 handle, which is sold separately and not included with this unit.

Key Features

• Go member verifies minimum material condition of 5/8-11 UNC internal threads
• 6H tolerance class per ANSI standards for general-purpose metric-equivalent fit
• NIST traceability certification included for calibration documentation requirements
• Steel construction for durability in production inspection environments
• Single-end configuration for dedicated Go inspection workflow
• Accepts Size 3 handle (handle not included)

Compatibility

Designed for use with a Size 3 plug gage handle, sold separately. Suitable for inspecting 5/8-11 UNC tapped holes held to 6H class tolerances per ANSI standards.

Installation Notes

Thread plug gages are installed and used by machinists or quality inspection personnel — no special tools are required beyond a compatible handle. Before use, clean the threaded hole and gage member of chips, oil, and debris to prevent false readings or gage wear. Apply light gage oil when checking production threads to extend gage life. Handle the gage carefully to avoid dropping, as impact damage can alter the thread form and invalidate calibration.