Spi 37-156-7 Plug Thread Gage M12x1.75 6H No Go

Product Description

The SPI 37-156-7 is a single-end plug thread gage designed to verify M12x1.75 internal threads to the 6H tolerance class using the No Go functional check. The gage member is inserted into a tapped hole; if it enters, the thread is oversized and out of tolerance. This tool is used on the shop floor or in inspection environments by machinists, quality technicians, and precision assemblers who need to confirm that threaded bores meet specification before parts move forward in production. The gage ships without a handle, which is ordered separately. Traceability documentation meets ANSI standards, with calibration traceable to NIST.

This No Go plug gage is suited for production inspection of M12x1.75 threaded holes in manufacturing, automotive, aerospace, and general mechanical assembly environments. It is a single-end design, meaning only the No Go member is present on this gage — a corresponding Go gage must be used separately to perform a complete thread qualification. The compact form factor makes it easy to use inline with production or at a dedicated inspection station.

Key Features

• No Go member confirms M12x1.75 internal threads are not oversized or out of 6H tolerance
• Single-end design for focused No Go inspection without a Go member on the same shank
• ANSI-traceable certification included; calibration traceable to NIST
• Handle not included — compatible with standard thread gage handles sold separately
• Lightweight at 0.132 pounds for easy handling during repetitive inspection tasks

Compatibility

Designed for use with standard plug thread gage handles sized to accept the shank diameter of this gage member. Handle must be sourced separately. Suitable for inspecting M12x1.75 6H tolerance class tapped holes in any material or application where that thread form is specified.

Installation Notes

Thread gages require no power and no permanent installation, but must be handled by qualified inspection or machining personnel familiar with go/no-go gauging practice. Store the gage in its protective case when not in use to prevent damage to the thread form. Do not force the No Go member into a threaded hole; entry under hand pressure alone indicates an out-of-tolerance condition. Periodic recalibration against NIST-traceable masters is recommended to maintain measurement integrity.