Spi 19-578-4 Class Zz Minus Plug Pin Gage 0.578 in

Product Description

The SPI 19-578-4 is a Class ZZ minus plug pin gage machined from steel for dimensional inspection of holes and bores at 0.578 inches nominal diameter. Class ZZ is the standard commercial-grade tolerance class used for general inspection work where tight gage tolerances are not required. This gage is manufactured to a minus tolerance of 0.000200 inches, meaning it will not exceed the nominal diameter, helping prevent false acceptance of undersized features. Machinists, quality technicians, and tool-room personnel use plug gages like this one to verify whether a drilled, reamed, or bored hole falls within a specified tolerance range during in-process or final inspection.

This gage is suited for production floor and inspection room use in metalworking, machining, and fabrication environments. It is used to check hole diameter acceptance on machined components, fixtures, and assemblies. The 0.578-inch nominal size is common in general mechanical and industrial applications. The minus grind ensures the gage member stays under nominal, which is standard practice for go-no-go inspection setups where the go gage must freely enter an acceptable hole.

Key Features

• Class ZZ tolerance classification for general commercial inspection use
• Minus grind keeps gage diameter at or below nominal to protect against false acceptance
• 0.000200-inch tolerance for reliable dimensional verification
• Steel construction for durability in production and inspection environments
• 0.578-inch nominal diameter for direct hole-size verification

Compatibility

Designed as a standard Class ZZ minus plug pin gage for use in general-purpose hole inspection applications across metalworking, machining, and fabrication operations requiring 0.578-inch nominal bore verification.

Installation Notes

Plug pin gages are handled and used by quality technicians and machinists following standard metrology practices. Clean the gage and the hole being inspected before use to prevent debris from affecting readings or damaging the gage surface. Do not force the gage into a hole; if resistance is met, the hole is undersized and forcing entry will damage the gage or the workpiece. Store in a protected case away from other tooling to prevent surface damage that would compromise dimensional accuracy.