Spi 34-394-7 Plug Thread Gage 7/16-14 3B Double End

Product Description

The SPI 34-394-7 is a double-end plug thread gage used to verify internal thread quality on 7/16-14 UNC threaded holes to the 3B tolerance class. One end carries the Go member, which must pass fully through the threaded hole to confirm minimum material condition. The opposite end carries the No Go member, which must not enter the hole, confirming the thread has not been cut oversized. The gage ships complete with a handle and includes a traceable calibration certification referenced to NIST standards. Machinists, quality technicians, and inspection personnel use this tool during in-process and final inspection to confirm thread conformance before assembly.

This gage is suited to production and inspection environments where 7/16-14 internal threads are machined or tapped in steel, aluminum, or similar materials. The double-end design consolidates Go and No Go checks into a single tool, reducing changeover time on the inspection bench. The 3B classification covers the standard tolerance range used in the majority of commercial and industrial fastener applications. A handle size 2 is included, making the tool ready to use directly out of the box.

Key Features

• Go and No Go members on a single double-end gage — one tool handles complete thread acceptance inspection
• 3B tolerance class — matches the standard commercial thread fit used in most industrial assemblies
• NIST-traceable calibration certification included — supports quality management documentation requirements
• Handle size 2 included — no additional handle purchase required
• Steel construction — provides wear resistance for repeated use in production inspection

Compatibility

Designed for inspection of 7/16-14 UNC internal threads held to the 3B tolerance class in accordance with NIST-referenced thread standards.

Installation Notes

Thread plug gages are handled and used by machinists and quality inspection technicians; no installation is required. Store the gage in a protected case when not in use to prevent damage to the precision thread members. Do not force the No Go member into a threaded hole. Periodic recalibration against a certified master is recommended to maintain measurement integrity over the life of the gage.