Spi 19-302-9 Class Zz Minus Plug Pin Gage 0.302 in

Product Description

The SPI 19-302-9 is a Class ZZ minus plug pin gage with a 0.302-inch nominal diameter, designed for go/no-go gauging and hole inspection in production and quality control environments. Built from steel, it checks whether a drilled, reamed, or bored hole falls within the specified tolerance band. The minus designation means the gage is manufactured to the low side of the nominal diameter, consistent with Class ZZ go-gage practice. With a tolerance of 0.0002 inches, this gage is suited for general-purpose inspection work where tight measurement certainty is required. Machinists, toolmakers, and quality technicians are the primary users.

This pin gage is used in machine shops, manufacturing facilities, and inspection departments to verify hole diameter conformance on machined parts. It is appropriate for checking drilled and reamed holes in metal, plastic, and composite workpieces. Class ZZ gages are the standard grade for general shop-floor use, as opposed to the tighter tolerances of Class Z or ZZ inspection gages used in controlled metrology labs. The single-pin format fits standard pin gage handles and sets for efficient use during in-process or final inspection routines.

Key Features

• 0.302-inch nominal diameter for precise hole verification at that size
• Class ZZ minus designation conforms to ANSI/ASME B89.1.5 go-gage standards
• Steel construction provides durability and wear resistance in shop environments
• 0.0002-inch tolerance ensures reliable conformance to Class ZZ accuracy requirements
• Compatible with standard pin gage handles for quick, ergonomic use

Compatibility

Designed as an OEM-style replacement or individual pin addition for standard pin gage handle sets used in general shop-floor hole inspection applications.

Installation Notes

Pin gages are installed by hand into a compatible pin gage handle — no special tools are required. Clean both the gage pin and the workpiece hole before use to prevent debris from affecting readings. Do not force the pin into an undersize hole, as this can cause galling or diameter distortion. Store pins in a protective case away from moisture to preserve the steel surface and dimensional integrity.