Spi 19-579-2 Class Zz Minus Plug Pin Gage 0.579 in

Product Description

The SPI 19-579-2 is a Class ZZ minus plug pin gage machined from steel, designed to verify bore and hole diameters to a high degree of dimensional accuracy. With a nominal diameter of 0.579 inches and a tolerance of 0.0002 inches, this gage provides reliable go/no-go measurement for quality control and inspection work in manufacturing, machining, and maintenance environments. The minus designation indicates the gage is ground to the lower boundary of the tolerance band, consistent with standard plug gage convention. Machinists, quality technicians, and tool room personnel use this type of gage for fast, repeatable hole verification on the shop floor or at an inspection station.

Class ZZ plug gages are suited for general-purpose inspection where close-tolerance Class Z or ZZ accuracy is required without the cost of master-grade tooling. The SPI 19-579-2 is appropriate for checking drilled, reamed, or bored holes in production runs, incoming inspection, and in-process quality checks. It is a single-ended pin gage and is typically used as part of a broader gage set or alongside a complementary go gage depending on the inspection protocol in place at the facility.

Key Features

• Nominal diameter of 0.579 inches for precise hole and bore verification
• Class ZZ minus tolerance of 0.0002 inches, ground to the lower tolerance boundary
• Steel construction for durability and dimensional stability under shop conditions
• Compact and lightweight at 0.2 pounds, suited for handheld use at the point of inspection
• Single-piece design with no moving parts for consistent, repeatable measurements

Compatibility

Designed as a general-purpose Class ZZ minus plug pin gage compatible with standard gage handle sets and pin gage holders sized for 0.579-inch diameter pins.

Installation Notes

Plug pin gages require no installation but should be handled and stored carefully to prevent surface damage that could affect measurement accuracy. Clean the gage and the bore being checked before use to remove debris, chips, or oil that could produce false readings. Do not force the pin into an undersized hole, as this can damage the gage or alter its calibration. Periodic recalibration against certified reference standards is recommended to maintain measurement traceability.