Spi 29-979-2 Class Zz Plus Plug Gage 0.979 in Dia

Product Description

The SPI 29-979-2 is a Class ZZ Plus plug gage used to verify the inside diameter of machined holes, bores, and drilled passages to a nominal size of 0.979 inches. It holds a tolerance of 0.0002 inches, which places it in the tighter ZZ Plus classification used where precise dimensional verification is required. The gage body is steel construction, providing durability and wear resistance during repeated use. Machinists, quality control technicians, and tool room personnel use plug gages like this one as part of go/no-go inspection routines on production floors and in metrology departments.

This gage is suited for inspecting holes in metal components across light manufacturing, precision machining, and job shop environments. It is used wherever a 0.979-inch nominal bore diameter must be verified against a dimensional tolerance. Common applications include incoming inspection of purchased parts, in-process checks on CNC-machined components, and final inspection before assembly. The steel construction holds up to frequent contact with ferrous and non-ferrous workpieces without significant wear over normal service life.

Key Features

• Class ZZ Plus classification for tighter tolerance plug gage inspection work
• 0.979-inch nominal diameter for direct bore verification
• 0.0002-inch tolerance provides precise dimensional control
• Steel construction resists wear during repeated use
• Single-piece package quantity — no minimum order beyond one unit

Compatibility

Designed as an OEM-style plug gage for use in standard metrology and quality inspection applications requiring a 0.979-inch nominal diameter Class ZZ Plus gage.

Installation Notes

Plug gages are handled and used by machinists and quality inspection personnel — no installation in the traditional sense applies. Store the gage in a protective case away from moisture to prevent corrosion on the steel surface. Clean the gage and the bore being checked before use to ensure accurate readings. Do not force the gage into a hole; if resistance is felt beyond normal snug fit, stop and re-inspect the bore dimension.