Spi 37-124-5 Plug Thread Gage M20x1.5 6H Single End Go

Product Description

The SPI 37-124-5 is a single-end Go plug thread gage designed to verify the minimum material condition of M20x1.5 internal threads classified to the 6H tolerance standard. This gage checks that a threaded hole has been cut within acceptable limits, allowing the mating fastener to engage properly. It is used during machining, fabrication, and quality-control inspection on the shop floor. Traceability certification is included per ANSI standards, and calibration is traceable to NIST. The handle is not included and must be sourced separately to mount and operate the gage. Machinists, quality technicians, and manufacturing inspectors are the primary users of this tool.

This plug thread gage is suited for verifying M20x1.5 tapped holes in production and inspection environments across metalworking, mechanical assembly, and general manufacturing applications. The Go member confirms that the threaded bore meets the low limit of the 6H tolerance class, ensuring proper fit with a mating M20x1.5 bolt or stud. It is appropriate for both in-process checks on the machine and final inspection at a quality station. Single-end design keeps the gage compact and reduces the chance of operator confusion when only Go verification is required at a given stage.

Key Features

• Go member checks M20x1.5 internal threads to 6H tolerance class
• Single-end configuration for dedicated Go inspection use
• ANSI traceability certification included; calibration traceable to NIST
• Compact gage size — 1.87 inches in height, 0.79 inches in width and length
• Handle not included — compatible with standard plug gage handles sold separately
• Lightweight at 0.22 pounds for easy bench and in-process use

Compatibility

Designed for use with M20x1.5 tapped holes held to the 6H internal thread tolerance class. Requires a separately purchased plug gage handle sized to accept this gage member.

Installation Notes

Thread gages should be installed into a compatible handle before use — do not attempt to operate the gage member by hand without a proper handle, as this can damage the gage or produce inaccurate results. Clean the threaded bore and the gage member before each use to remove chips, coolant, and debris that could affect reading accuracy. Store the gage in its case when not in use to protect the thread form from nicks and corrosion. Periodic recalibration against a NIST-traceable standard is recommended to maintain measurement integrity.