3/8 inch x 5-1/2 inch Black Steel Nipple

3/8" x 5-1/2" Black Steel Nipple – Threaded Connector for Gas and Utility Piping

The 3/8 inch x 5-1/2 inch Black Steel Nipple is a straight, male-threaded pipe segment used to connect fittings or extend pipe runs in low- to moderate-pressure piping systems. Fabricated from carbon steel and coated with a black oxide finish, this nipple is suitable for applications involving natural gas, compressed air, steam, or non-potable water lines in residential, commercial, and light industrial environments.

This component is typically used when a precise extension length is required between threaded components. Its compatibility with standard NPT connections ensures consistent performance when installed in accordance with ANSI and ASTM standards.

Key Features

• ✅ Material: Welded or seamless carbon steel
• ✅ Coating: Black oxide finish for dry interior environments
• ✅ Connection Type: Male NPT x Male NPT – per ANSI/ASME B1.20.1
• ✅ Length: 5-1/2 inches
• ✅ Schedule: Typically Schedule 40 unless otherwise noted

Applicable Standards

• ASTM A733: Standard specification for pipe nipples including dimensional tolerances and end preparation
• ASTM A53 or A106: Applicable base material standards for carbon steel pipe
• ASME B1.20.1: Standard for tapered pipe threads (NPT)

Installation Guidelines

Apply PTFE tape or approved thread sealant to each male thread prior to installation. Engage hand-tight and complete assembly with a pipe wrench to recommended torque. Over-tightening may damage threads or connected components. This fitting is not suitable for potable water use unless protected or rated accordingly.

Typical Applications

The 3/8" x 5-1/2" black steel nipple is commonly used in:

• Gas distribution lines (natural gas, propane)
• Low-pressure steam piping
• Compressed air systems
• General-purpose mechanical or utility piping

Material Note

Black steel pipe and fittings are intended for use in systems not exposed to corrosive fluids or outdoor moisture unless protected. For potable water or corrosion-prone installations, galvanized or coated alternatives should be considered.

The 3/8" x 5-1/2" Black Steel Nipple offers a reliable, code-compliant solution for rigid piping systems requiring threaded connections in utility, HVAC, or fuel gas service lines. Engineered for dimensional accuracy and strength, it supports professional-grade performance in new installations and retrofits alike.