Spi 19-131-2 Class Zz Minus Plug Pin Gage 0.131 in

Product Description

The SPI 19-131-2 is a Class ZZ minus plug pin gage with a 0.131-inch nominal diameter, used to verify bore and hole dimensions in precision machining and inspection work. The minus tolerance convention means the gage is manufactured undersized from nominal, producing a tolerance of 0.0002 inches. This design ensures the gage enters an acceptable hole without interference, confirming the bore has been machined to at least the minimum acceptable size. Constructed from steel, it delivers the hardness and dimensional stability required for repeatable use in quality control environments. Machinists, toolmakers, and quality inspectors are the primary users of this type of gage.

Class ZZ plug gages are the standard go/no-go reference tool for production inspection of drilled, reamed, or bored holes. This particular gage is suited for light industrial and commercial manufacturing environments where confirming a 0.131-inch diameter feature is part of in-process or final inspection. The minus designation makes it appropriate as a go gage, confirming minimum material condition acceptance. It is used by machinists on the shop floor, quality control technicians at inspection stations, and toolroom personnel performing fixture and jig verification.

Key Features

• Class ZZ tolerance grade for standard production inspection applications
• Minus tolerance convention: gage is undersized from nominal for go-gage use
• 0.0002-inch tolerance for repeatable dimensional verification
• 0.131-inch nominal diameter for checking small-bore features
• Steel construction for durability and dimensional stability

Compatibility

Designed as a standard Class ZZ minus plug pin gage for use in quality inspection of machined bores and holes at a 0.131-inch nominal diameter.

Installation Notes

Plug pin gages do not require installation in the traditional sense, but proper handling is essential to maintain accuracy. Store the gage in a protective case and allow it to reach ambient temperature before use, as thermal expansion can affect readings. Clean the gage and the bore being checked before each measurement to remove chips, coolant, or debris. Do not force the gage into a hole; if resistance is felt, the feature is undersize and should be returned for further machining.