3/4 inch x 3-1/2 inch Black Steel Nipple

3/4" x 3-1/2" Black Steel Pipe Nipple – Threaded Schedule 40 Extension

The 3/4" x 3-1/2" Black Steel Nipple is a Schedule 40 pipe fitting used to extend piping runs or connect two female-threaded components. Fabricated from welded or seamless carbon steel pipe, this nipple features NPT (National Pipe Taper) male threads on both ends for compatibility with standard fittings in low- to medium-pressure systems.

Commonly used in applications including gas distribution, hydronic heating, and industrial piping systems, this component supports structural integrity, pressure retention, and secure mechanical connections within ferrous piping networks.

Performance and Material Specifications

• ✅ Material: Carbon steel with black oxide coating (commonly ASTM A53 Grade A or equivalent)
• ✅ Wall Thickness: Schedule 40, suitable for general utility, steam, gas, and water applications
• ✅ Threading: NPT male x NPT male per ASME B1.20.1 standard
• ✅ Length: 3-1/2 inches overall, including threaded sections
• ✅ Working Pressure: Dependent on system design, typically up to 150 PSI for steam/gas services

Installation Guidelines

Use appropriate thread sealant or PTFE tape on male threads to ensure a leak-resistant connection. Avoid over-torquing, which can deform threads and compromise sealing integrity. Installation must follow ANSI and local plumbing or mechanical code requirements, particularly in fuel gas and steam applications.

Applications

This black steel nipple is commonly used in mechanical, industrial, and commercial systems for fluid or gas transport. Typical applications include gas line extensions, compressed air systems, steam piping, and water supply networks where galvanized materials are not specified. Its black oxide finish is intended for indoor or dry system use only and should not be installed in potable water lines unless otherwise specified.

Standards and Compliance

This component is typically manufactured in accordance with ASTM A733 and is threaded per ASME B1.20.1. For use in pressure piping systems, compatibility with ASTM A53, ASTM A106, or equivalent base pipe materials is assumed. Always verify material certifications and system requirements prior to use in regulated applications.

Technical Summary

• Nominal Size: 3/4 inch
• Length: 3-1/2 inches
• Material: Black carbon steel, Schedule 40
• Thread Standard: NPT (ASME B1.20.1)
• Certifications: Complies with ASTM A53 and A733 dimensional standards