Spi 37-108-8 Plug Thread Gage M4.5x0.75 6H Single End Go

Product Description

The SPI 37-108-8 is a single-end Go plug thread gage designed to verify internal thread conformance to the M4.5x0.75 metric thread form at 6H tolerance class. Used during inspection to confirm that a tapped hole has been cut correctly and will accept a mating fastener within specification, this gage is a standard tool in quality-control and machining operations. The gage member measures 1.28 inches in length and 0.18 inches in diameter and weighs 0.066 pounds. Traceability certification is included to ANSI standards with NIST traceability, supporting documented inspection processes. A handle is not included and must be sourced separately.

This gage is suited for machine shops, production floors, and metrology labs where metric threaded holes require dimensional verification before assembly. The M4.5x0.75 thread size is commonly found in precision mechanical assemblies and instrument hardware. The single-end Go configuration checks that the thread is within the minimum material condition, confirming the hole is not undersize. It is appropriate for both incoming inspection and in-process quality checks performed by machinists, quality technicians, and inspection personnel.

Key Features

• Go member checks M4.5x0.75 internal threads for minimum material condition conformance
• 6H tolerance class per standard metric thread specifications
• ANSI traceability certification with NIST traceability included
• Single-end design for straightforward Go-only inspection tasks
• Compact gage member: 1.28 inches long, 0.18 inches in diameter
• Handle not included — compatible with standard plug gage handles sold separately

Compatibility

Designed for use with standard plug gage handles sized for the gage member diameter. Verify handle compatibility with the 0.18-inch gage member diameter before ordering a handle separately.

Installation Notes

Plug thread gages are used by machinists and quality inspection personnel and do not require power or special installation. Before use, clean the tapped hole and gage member of chips, oil, and debris to avoid false readings or gage damage. Apply light hand pressure only when engaging the gage — never force or torque a plug gage into a thread. Store the gage in a protective case and calibrate on a schedule consistent with your quality management system requirements.