Spi 34-443-2 Pipe Thread Plug Gage 2-1/2-8 Npt Class L-1

Product Description

The SPI 34-443-2 is a tapered pipe thread plug gage used to inspect and verify NPT internal threads to Class L-1 tolerance. It is designed for single-end use with a size 6 handle and covers the 2-1/2-8 thread size designation. This gage confirms that threaded pipe connections meet dimensional requirements per ANSI B1.20.1, helping machinists, pipefitters, and quality control technicians catch out-of-tolerance threads before assembly. Each unit ships with a NIST Traceability Certificate, supporting documentation requirements in regulated manufacturing and inspection environments.

This plug gage is applied in pipe thread inspection across industrial, mechanical, and plumbing fabrication settings. It is suited for production floor use and incoming inspection of threaded pipe fittings, valves, and manifold bodies where NPT Class L-1 compliance is required. The 2-1/2-8 thread size makes it relevant to larger-diameter piping assemblies common in commercial and industrial applications. A licensed machinist, quality technician, or journeyman pipefitter typically performs this type of thread verification.

Key Features

• Tapered NPT-L1 thread form per ANSI B1.20.1 for pipe thread inspection
• 2-1/2-8 thread size for larger-diameter pipe applications
• Class L-1 tolerance for standard functional thread acceptance
• Single-end configuration with a size 6 handle for controlled engagement
• Includes NIST Traceability Certificate for calibration documentation compliance

Compatibility

Designed for inspection of NPT internal threads at the 2-1/2-8 Class L-1 designation in accordance with ANSI B1.20.1.

Installation Notes

Thread plug gages are inspection tools and do not require permanent installation. Apply thread gage lubricant or light oil before use to protect gage threads and ensure accurate engagement. Do not force the gage into a threaded part; resistance beyond hand-tight engagement indicates a non-conforming thread. Store the gage in its protective case and return it for periodic recalibration per your facility quality plan.