Spi 19-745-9 Class Zz Minus Plug Pin Gage 0.745 in

Product Description

The SPI 19-745-9 is a Class ZZ minus plug pin gage machined from steel and used to verify that a hole or bore falls within a specified dimensional tolerance. At 0.745 inches in diameter with a tolerance of 0.0002 inches, this gage is sized for precision go/no-go inspection work in manufacturing, machining, and quality control environments. Class ZZ is the standard tolerance class for plug gages used in general inspection of production parts where high-volume checking is required. Machinists, quality technicians, and tool room professionals use this type of gage daily on the shop floor.

This pin gage is suited for inspecting drilled, reamed, or bored holes in production parts across metalworking, fabrication, and general manufacturing settings. The minus designation indicates the gage is ground to the lower end of the tolerance band, making it appropriate for go-gage applications where confirming minimum acceptable hole size is the primary task. It is commonly used as part of a larger gage set or as a standalone replacement gage.

Key Features

• 0.745 inch nominal diameter for direct hole inspection at that bore size
• Class ZZ tolerance class — suitable for general production inspection
• Minus designation — ground to the lower tolerance boundary for go-gage use
• Steel construction for durability and dimensional stability under shop conditions
• 0.0002 inch tolerance ensures reliable pass/fail discrimination

Compatibility

Designed as a standard Class ZZ minus plug pin gage for use in general production inspection of 0.745 inch diameter holes and bores.

Installation Notes

Plug pin gages are handled and used by machinists and quality control technicians without special tooling. Keep the gage clean and lightly oiled to prevent corrosion and maintain dimensional accuracy. Do not force the gage into a bore — excessive insertion force can damage both the gage and the workpiece. Store in a protective case away from temperature extremes to preserve calibration integrity.