Spi 37-162-5 Plug Thread Gage M18x2.5 6H Class No Go

Product Description

The SPI 37-162-5 is a single-end plug thread gage designed to verify M18x2.5 internal threads to a 6H tolerance class using the No Go inspection method. It is used to confirm that a threaded hole has not been cut oversize or is otherwise out of tolerance — the No Go member must not fully enter a conforming thread. This gage is a precision inspection tool manufactured to ANSI standards and traceable to NIST. Handle is not included and must be sourced separately. Machinists, quality control technicians, and toolroom personnel are the primary users of this gage in manufacturing and maintenance environments.

This gage is suited for inspecting M18x2.5 threaded holes in production parts, fixtures, and assemblies across general manufacturing, automotive, aerospace, and industrial maintenance settings. It is used during in-process inspection or final quality checks where metric thread conformance to 6H class tolerances must be verified. Single-end configuration means this gage checks the No Go condition only; a separate Go gage is required for full go/no-go thread verification.

Key Features

• No Go plug member for M18x2.5 metric internal thread inspection
• 6H tolerance class conformance for standard metric thread fits
• Single-end configuration — dedicated No Go function
• Manufactured to ANSI standards with NIST traceability certification included
• Handle not included — compatible with standard plug gage handles sold separately

Compatibility

Designed for use with standard plug gage handles sized to accept M18x2.5 single-end gage members. Intended for inspection of M18x2.5 internally threaded components held to 6H tolerance class per ANSI metric thread standards.

Installation Notes

A licensed machinist or QC technician should perform thread gage inspections in accordance with applicable shop standards and ANSI gaging practices. Before use, clean the threaded bore and gage member to remove chips, oil, and debris that could affect results. Do not force the No Go member into the thread — if resistance is met, that is the expected pass condition. Store the gage in a protective case away from other metal tooling to prevent damage to the gage threads.