Spi 29-437-1 Class Zz Plus Plug Gage 0.437 Inch

Product Description

The SPI 29-437-1 is a Class ZZ Plus plug gage designed for verifying hole diameters in precision machining and quality control applications. It measures a nominal diameter of 0.437 inches with a tolerance of 0.0002 inches, providing the close tolerance control required for accurate go/no-go inspection work. Constructed from steel, this plug gage is built to withstand repeated use in shop environments. Machinists, tool and die makers, and quality inspection personnel use plug gages like this one to confirm that bored, drilled, or reamed holes fall within specified dimensional limits before parts move to the next stage of production.

This gage is suited for use in manufacturing, job shop, and inspection room environments where hole diameter verification is required. It is appropriate for checking holes in metal, plastic, or composite workpieces where a 0.437-inch nominal diameter is the target dimension. Class ZZ Plus designates a tolerance grade commonly used for inspection of standard commercial-tolerance work, making this gage a practical choice for general production inspection rather than laboratory-grade metrology.

Key Features

• Nominal measurement diameter of 0.437 inches for direct hole verification
• Class ZZ Plus tolerance grade at 0.0002 inches for reliable go/no-go inspection
• Steel construction for durability and dimensional stability under shop conditions
• Compact and lightweight at 0.2 pounds for easy one-handed use
• Single-piece package quantity — ready to use out of the box

Compatibility

Designed as an OEM-style inspection gage for use wherever a 0.437-inch nominal diameter plug gage meeting Class ZZ Plus tolerance standards is specified.

Installation Notes

Plug gages are handled and used by machinists and quality inspection personnel — no power tools or utility shutoffs are required. Clean and deburr the hole being inspected before inserting the gage to prevent damage to the gage surface and to ensure accurate readings. Store the gage in a protective case away from abrasive materials to preserve its tolerance integrity. Periodic calibration against a traceable standard is recommended to maintain measurement accuracy over time.