Spi 19-255-9 Class Zz Minus Plug Pin Gage 0.255 in

Product Description

The SPI 19-255-9 is a Class ZZ minus plug pin gage machined to a nominal diameter of 0.255 inches with a minus tolerance of 0.0002 inches. Pin gages are precision inspection tools used to verify hole diameters, slot widths, and bore sizes to a defined tolerance class. The Class ZZ designation indicates a working-grade gage suitable for production floor inspection and go/no-go gauging tasks. Constructed from steel, this gage delivers the hardness and dimensional stability required for repeatable measurement across production runs. Machinists, quality control technicians, and tool and die professionals rely on pin gages like this one to confirm that drilled, reamed, or punched features conform to drawing tolerances.

This gage is used in manufacturing, fabrication, and metrology environments where hole size verification is part of the inspection process. It is appropriate for checking features in metal, plastic, and composite workpieces. The 0.255-inch diameter and minus tolerance configuration makes it suited for checking the low limit of a tolerance band, confirming that a hole is at or above the minimum acceptable size. It fits into standard pin gage handles or can be used as a standalone plug to verify clearance fits and location holes on production parts.

Key Features

• Nominal diameter of 0.255 inches for precise hole and bore inspection
• Class ZZ minus tolerance of 0.0002 inches for working-grade go/no-go gauging
• Steel construction for hardness and long-term dimensional stability
• Compatible with standard pin gage handles for ergonomic production use
• Single-piece packaging suitable for individual replacement or kit supplementing

Compatibility

Designed as a working-grade Class ZZ plug pin gage for use with standard pin gage handle sets and in general production inspection applications requiring a 0.255-inch nominal diameter.

Installation Notes

Pin gages should be handled with clean, dry hands or lint-free gloves to prevent corrosion from skin oils. Before use, verify the gage surface is free of burrs, debris, or damage that could affect measurement accuracy. Store in a protective case away from temperature extremes to maintain dimensional integrity. Calibration intervals should follow the shop quality plan or applicable metrology standards such as ASME B89.1.5.