Spi 19-555-2 Class Zz Minus Plug Pin Gage 0.555 in

Product Description

The SPI 19-555-2 is a Class ZZ minus plug pin gage designed for go/no-go dimensional inspection of machined bores and holes. Sized at 0.555 inches in diameter with a minus tolerance of 0.0002 inches, this gage checks that an interior feature meets its minimum acceptable size. Constructed from steel for wear resistance and dimensional stability, it is a standard tool in quality control and machine shop inspection workflows. Metrology technicians, machinists, and QC inspectors use this type of gage for high-repetition functional inspection tasks.

Class ZZ plug gages are the most widely used grade for general-purpose shop-floor inspection. This gage is suited for checking drilled, reamed, or bored holes in production and job-shop environments where consistent go/no-go verification is required. The minus designation means the gage is manufactured undersized relative to the nominal diameter, making it appropriate for use as a go member in a plug gage set or as a standalone minus-tolerance reference gage.

Key Features

• Class ZZ tolerance grade for general-purpose shop and production inspection
• Minus plug configuration with 0.0002 inch tolerance for precise undersized verification
• 0.555 inch nominal diameter for direct bore and hole inspection
• Steel construction provides durability and dimensional stability under repeated use
• Compact and lightweight at 0.2 pounds for easy single-hand operation

Compatibility

Designed as a standard Class ZZ minus plug pin gage for use in general machining and quality control inspection applications requiring 0.555 inch bore verification.

Installation Notes

Plug pin gages should be handled and stored carefully to prevent damage to the precision ground surface. Before use, clean the gage and the bore being checked with a lint-free cloth to remove chips, coolant, or debris that could affect the reading. Do not force the gage into a hole; apply light, consistent hand pressure only. Periodic recalibration against a certified master is recommended to confirm gage integrity over time.