Spi 19-549-5 Class Zz Minus Plug Pin Gage 0.549 in

Product Description

The SPI 19-549-5 is a Class ZZ minus plug pin gage with a nominal diameter of 0.549 inches, manufactured from steel. Pin gages are used to verify hole diameters, slot widths, and bore tolerances in precision machining and inspection work. This gage conforms to Class ZZ standards, which designate it for general-purpose go/no-go inspection in production environments. The minus designation indicates the gage is ground to the lower limit of the nominal size, consistent with standard plug gage practice for go-gage applications. With a tolerance of 0.0002 inches, it provides reliable dimensional verification for machinists, quality control inspectors, and toolroom personnel.

Class ZZ plug pin gages are standard tools in machine shops, manufacturing facilities, and quality assurance departments. They are used to inspect drilled, reamed, or bored holes to confirm compliance with engineering tolerances. This 0.549-inch gage is suited for both incoming inspection and in-process quality checks on metal, plastic, and composite workpieces. Machinists and QC technicians across automotive, aerospace, and general manufacturing industries rely on pin gages for fast, repeatable go/no-go verification without the need for specialized measuring instruments.

Key Features

• Nominal diameter of 0.549 inches for precise hole and bore inspection
• Class ZZ tolerance rating at 0.0002 inches for general-purpose production inspection
• Minus designation ground to lower limit, suitable for go-gage applications
• Steel construction for durability in shop and inspection environments
• Single-piece gage for straightforward go/no-go measurement workflow

Compatibility

Designed as an OEM-style replacement or supplemental gage compatible with standard pin gage handle sets and gage block accessories sized for 0.549-inch diameter plug gages.

Installation Notes

Pin gages are handled and used by machinists and quality control inspectors and require no power source or fastening. Store gages in a protective case and apply a light coat of rust-preventive oil when not in use to maintain surface integrity. Do not force the gage into a hole; if resistance is encountered, the hole is undersize. Clean the gage and the workpiece bore before inspection to prevent debris from affecting readings.