Spi 19-442-3 Class Zz Minus Plug Pin Gage 0.442 in

Product Description

The SPI 19-442-3 is a Class ZZ minus plug pin gage machined to a 0.442-inch nominal diameter with a tolerance of 0.0002 inches. Pin gages in this class are used for go/no-go inspection of drilled, reamed, or punched holes, confirming that a hole falls within its specified size limits. The minus designation means the gage is ground to the lower boundary of the tolerance range, making it suitable for verifying minimum hole size. Constructed from steel, this gage delivers the hardness and wear resistance required for repeated use in production or inspection environments. Metrology technicians and quality-control personnel are the primary users.

Class ZZ plug gages are intended for general-purpose inspection work where ultra-precision master-grade accuracy is not required. They are commonly used in machine shops, fabrication facilities, and manufacturing lines to check hole diameters in metal, plastic, or composite workpieces. Typical applications include incoming material inspection, in-process quality checks, and final acceptance testing of machined components. The 0.442-inch diameter positions this gage for use with a broad range of standard hole sizes found in mechanical assemblies.

Key Features

• Class ZZ minus tolerance ground to 0.0002 inches for reliable minimum-hole verification
• 0.442-inch nominal diameter covers a common range of drilled and reamed hole sizes
• Steel construction provides hardness and durability for repetitive inspection use
• Minus designation identifies this as a lower-boundary gage for go/no-go procedures
• Single-piece packaging suitable for individual replacement or kit supplementation

Compatibility

Designed as a general-purpose plug pin gage for go/no-go hole inspection of 0.442-inch nominal diameter features in standard machined or fabricated workpieces. Compatible with standard pin gage handles and gage blocks used in typical metrology setups.

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 scoring that could affect measurement accuracy. Apply a light film of instrument oil for storage to prevent rust. Gage use and calibration practices should follow applicable shop quality standards such as those outlined in ASME B89 or equivalent metrology guidelines.