Spi 34-327-7 Plug Thread Gage 7/8-14 6H Single End No Go

Product Description

The SPI 34-327-7 is a single-end No Go plug thread gage used to verify internal thread quality on 7/8-14 UNF threaded bores. Manufactured from steel to 6H classification tolerances, this gage checks that a tapped hole has not been cut oversize or out of tolerance. A No Go gage should not pass fully through an acceptable thread — if it does, the part is out of spec and should be rejected. A Size 4 handle is required for use but is not included with this gage. This tool is used in precision machining, quality control, and maintenance environments where thread fit and fastener integrity are critical.

This gage is suited for inspection of 7/8-14 UNF threaded components in industrial manufacturing, maintenance and repair operations, and quality assurance departments. It is appropriate for use wherever internal threads must be verified against ANSI standards, including aerospace, hydraulic fittings, and general mechanical assemblies. The 6H tolerance class is the standard fit classification for most commercial UNF applications. A traceability certification traceable to NIST is included, supporting documentation requirements for regulated inspection environments.

Key Features

• No Go single-end design verifies threads are not oversize or out of tolerance
• 7/8-14 UNF thread size with 6H classification tolerance
• Steel construction for durability and dimensional stability
• NIST-traceable certification included for documented quality programs
• Conforms to ANSI and NIST standards
• Requires a Size 4 handle, sold separately

Compatibility

Designed for inspection of 7/8-14 UNF internal threads to 6H class tolerance per ANSI standards. Requires a Size 4 plug gage handle, not included.

Installation Notes

Thread gages should be handled and stored carefully to prevent nicks or corrosion that could affect dimensional accuracy. Before use, clean both the gage and the threaded bore to remove chips, oil, or debris. A No Go gage should never be forced into a threaded hole — if resistance is not felt within the first few turns, the thread may be out of tolerance. Inspection personnel should follow applicable quality procedures and handle the gage with clean gloves or lint-free cloth to preserve the calibrated surface finish.