Spi 37-139-3 Plug Thread Gage M1.6x0.35 6H No Go

Product Description

The SPI 37-139-3 is a single-end plug thread gage used to verify that internal threads do not exceed the maximum material condition for M1.6x0.35 metric threads at 6H tolerance class. The No Go member is used in the go/no-go inspection process: if the No Go end enters the threaded hole, the part is out of tolerance and rejected. This gage is used by machinists, quality technicians, and manufacturing inspectors working with small-diameter metric-threaded components. The handle is not included and must be sourced separately. Traceability certification conforms to ANSI standards traceable to NIST.

This gage is suited for inspection of M1.6x0.35 fine-pitch internal threads commonly found in precision components, electronics hardware, and small mechanical assemblies. It applies to production-floor inspection, incoming inspection, and quality audits where 6H thread tolerance verification is required. The No Go function isolates oversize or out-of-tolerance thread conditions in accordance with ANSI and NIST-traceable calibration standards.

Key Features

• No Go member for M1.6x0.35 internal thread inspection at 6H tolerance class
• Single-end design for dedicated No Go inspection operations
• ANSI traceability certification included, traceable to NIST
• Handle not included — compatible with standard plug gage handles sold separately
• Compact form factor suited for small-diameter thread verification

Compatibility

Designed for use with standard plug gage handles sold separately. Applies to inspection of M1.6x0.35 internal threads manufactured to 6H tolerance class per applicable ANSI metric thread standards.

Installation Notes

Insert the No Go member by hand into the threaded hole being inspected — do not force or torque the gage. If the No Go end enters the thread, the part fails inspection and should be rejected or reworked. Store the gage in a protective case when not in use to prevent damage to the precision ground surfaces. Calibration should be verified periodically against a NIST-traceable reference standard.