Spi 19-395-3 Class Zz Minus Plug Pin Gage 0.3950 in

Product Description

The SPI 19-395-3 is a Class ZZ minus plug pin gage machined from steel and used to inspect and verify bore diameters in precision manufacturing and quality control environments. It measures a nominal diameter of 0.3950 inches with a tolerance of 0.0002 inches, classifying it as a Class ZZ minus gage — the minus designation indicating the gage is ground to the lower boundary of the tolerance range. At 0.2 pounds, this single-piece pin gage is compact and suited for bench-top inspection work. Machinists, toolmakers, and quality technicians use plug gages like this to confirm that drilled, reamed, or bored holes meet dimensional specifications.

This plug pin gage is used in precision inspection applications across machine shops, manufacturing facilities, and quality assurance departments. It is appropriate for checking hole sizes in metal, plastic, or composite workpieces where a go or no-go verification method is required. Class ZZ gages are generally applied to commercial-grade tolerance inspection rather than master or reference gage applications. The steel construction makes the 19-395-3 suitable for general production inspection in industrial environments.

Key Features

• 0.3950 inch nominal measurement diameter for precise bore inspection
• Class ZZ minus designation ground to the lower boundary of the tolerance range
• 0.0002 inch tolerance for reliable commercial-grade dimensional verification
• Steel construction provides durability for repeated production use
• Lightweight at 0.2 pounds for comfortable handheld inspection

Compatibility

Designed as an OEM-style replacement or standard inspection tool compatible with Class ZZ plug gage handle sets and holders used in general precision measurement applications.

Installation Notes

Plug pin gages are handled and used by machinists, toolmakers, and quality control technicians — not typically installed in a permanent assembly. Store the gage in a protective case when not in use to prevent damage to the ground surface. Clean the gage pin and the hole being measured before inspection to avoid false readings from debris or burrs. Avoid dropping or forcing the gage into undersized bores, as this can damage the precision-ground surface and alter the measurement accuracy.