Spi 29-144-3 Class Zz Plus Plug Gage 0.144 in Dia

Product Description

The SPI 29-144-3 is a Class ZZ Plus plug gage designed for precise go/no-go dimensional inspection of small-diameter holes and bores. Measuring 0.144 inches in diameter with a tolerance of 0.0002 inches, this gage delivers the accuracy required for quality control on machined components and assemblies. Constructed from steel for durability and dimensional stability, the 29-144-3 is a standard tool in machine shops, manufacturing facilities, and precision-assembly environments. Metrology technicians and machinists use it to verify that drilled, reamed, or punched holes fall within specified tolerances before parts advance through production.

This plug gage is suited for applications requiring fine-tolerance hole verification in manufacturing and inspection settings. Its small 0.144-inch diameter makes it appropriate for checking tight-clearance holes in precision components such as fastener holes, pin locations, and similar features. Class ZZ Plus designation indicates it meets the tolerance class specified for workshop-grade go/no-go gages, making it a reliable choice for production floor inspection as well as incoming quality checks.

Key Features

• 0.144-inch measurement diameter for small-bore inspection
• 0.0002-inch tolerance conforming to Class ZZ Plus standards
• Steel construction for wear resistance and dimensional stability
• Compact and lightweight at 0.2 pounds for easy single-hand use
• Single-piece packaging suitable for individual workstation use

Compatibility

Designed as an OEM-style replacement or direct addition to standard plug gage sets for go/no-go inspection of 0.144-inch nominal diameter holes in general manufacturing and quality-control applications.

Installation Notes

Plug gages are handled and used by metrology technicians and machinists — no power tools or energy sources require lockout before use. Keep the gage clean and lightly oiled when stored to prevent corrosion on steel surfaces. Never force the gage into a hole; apply light, consistent hand pressure only to avoid damaging the gage or the workpiece. Periodic recalibration against traceable standards is recommended to maintain measurement integrity.