Spi 34-438-2 Pipe Thread Plug Gage 3/4-14 Npt Class L-1

Product Description

The SPI 34-438-2 is a tapered pipe thread plug gage used to verify the accuracy of female NPT pipe threads to Class L-1 tolerance standards. Conforming to ANSI B1.20.1, it checks thread form, taper, and pitch on 3/4-14 NPT-threaded ports and fittings. The single-end design uses a Handle Size 4 and ships with a NIST Traceability Certificate, making it suitable for documented quality control environments. Licensed plumbers, pipefitters, mechanical inspectors, and QC technicians use this gage in production, field verification, and incoming inspection of threaded pipe connections.

This gage is designed for use on 3/4-14 NPT female threads found across plumbing, HVAC, gas piping, and industrial piping systems. It is the appropriate tool when verifying that a tapped port or pipe fitting meets L-1 engagement tolerances before assembly. The included NIST Traceability Certificate supports ISO and quality management documentation requirements, making it compatible with shop-floor and laboratory inspection workflows.

Key Features

• Tapered NPT-L1 thread form per ANSI B1.20.1 and NIST standards
• Checks 3/4-14 NPT female threads to Class L-1 tolerance
• Single-end configuration with Handle Size 4 for controlled torque application
• NIST Traceability Certificate included for quality management documentation
• UNSPSC Code 41111600 for procurement and catalog classification

Compatibility

Designed for inspection of 3/4-14 NPT female threaded connections in plumbing, HVAC, gas piping, and industrial piping applications where Class L-1 thread verification is required.

Installation Notes

Thread plug gages are inspection tools and are installed by hand into the female thread under controlled, gentle engagement — never forced with power tools or excessive torque. Always ensure the mating thread is clean and free of debris before gaging. Store the gage in its protective case when not in use to preserve calibration integrity. Refer to ANSI B1.20.1 and applicable quality procedures for correct go/no-go acceptance criteria.