Spi 34-435-8 Pipe Thread Plug Gage 1/4-18 Npt Class L-1

Product Description

The SPI 34-435-8 is a tapered pipe thread plug gage used to verify the accuracy and conformance of internal NPT pipe threads. Manufactured to ANSI B1.20.1 standards, this Class L-1 gage checks that female pipe thread engagement length falls within acceptable tolerance. It ships with a NIST Traceability Certificate, making it suitable for use in quality-controlled shop environments where documented calibration records are required. The gage features a Handle Size 3 and is configured as a single-end tool. It weighs 1 pound and is a direct-use inspection instrument for machinists, pipefitters, and quality assurance technicians working with threaded pipe fittings and assemblies.

This gage is designed for inspecting 1/4-18 NPT internal tapered pipe threads in production, maintenance, and quality control settings. It is appropriate for use in industrial, commercial, and mechanical contracting environments where pipe thread integrity must be verified prior to assembly. Single-end configuration keeps the tool compact and straightforward to use at a bench or in-line inspection station. Trades and inspection departments working with NPT-threaded fittings in plumbing, HVAC, and industrial piping applications will find this gage applicable to standard inspection workflows.

Key Features

• Class L-1 tolerance classification per ANSI B1.20.1 for NPT tapered pipe thread inspection
• Inspects 1/4-18 NPT internal tapered pipe threads
• Includes NIST Traceability Certificate for documented calibration compliance
• Single-end design with Handle Size 3 for straightforward bench or field use
• Conforms to ANSI B1.20.1 and NIST standards

Compatibility

Designed for use with 1/4-18 NPT internal tapered pipe threads. Suitable for inspection of NPT-threaded fittings, valves, and pipe assemblies conforming to ANSI B1.20.1.

Installation Notes

This is a precision inspection gage, not an installation component. Handle with clean, dry hands or gloves to prevent corrosion from skin contact. Store in a protective case when not in use to preserve calibration integrity. Gage should be used and stored in accordance with applicable metrology and quality management procedures.