Spi 37-113-8 Plug Thread Gage M8x1.25 6H Single End Go

Product Description

The SPI 37-113-8 is a single-end Go plug thread gage designed to verify that an M8x1.25 internally threaded feature meets the minimum material condition required by the 6H tolerance class. The gage member enters the threaded bore and, when it passes through completely, confirms the thread form and pitch diameter fall within the acceptable Go limit. This type of gage is a core inspection tool in machining, fabrication, and assembly environments where metric fastener threads must meet dimensional standards. The handle is not included and must be sourced separately to match the gage shank diameter.

This gage is suited for production floor inspection and quality-control bench work in manufacturing, automotive, aerospace, and general industrial settings. It is used wherever M8x1.25 metric threads are tapped into components and must be verified for conformance before assembly. Single-end Go gages are commonly paired with a separate No-Go gage to complete a full thread acceptance inspection per applicable tolerancing standards.

Key Features

• Go member verifies minimum material condition of M8x1.25 internal threads
• 6H tolerance class — standard fit classification for commercial metric fastener threads
• Single-end design for streamlined Go-only inspection routines
• ANSI traceability certification included for audit and calibration documentation
• Calibrated to NIST-traceable standards
• Handle not included — compatible with standard plug gage handles sized to the shank

Compatibility

Designed for inspection of M8x1.25 internally threaded workpieces held to the 6H tolerance class. Requires a separately purchased plug gage handle sized to fit the gage shank.

Installation Notes

Plug thread gages are used by machinists, quality technicians, and inspection personnel — not installed in a system, but handled during part inspection. Always clean the threaded bore and the gage member before use to prevent false readings from chips or coolant. Apply light, even hand pressure when inserting the Go member — never force a plug gage with tools, as this can damage the gage and yield inaccurate results. Store the gage in its case away from other metal tooling to prevent contact damage to the precision thread form.