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

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

The 1/2" x 3-1/2" Black Steel Nipple is a Schedule 40 welded steel fitting designed for use in systems requiring threaded pipe connections. Manufactured to ANSI/ASME B1.20.1 standards, it features NPT (National Pipe Thread) male threads on both ends, allowing for secure mechanical connections without welding or soldering.

This pipe nipple is suitable for use in non-potable systems such as gas distribution, hydronic heating loops, low-pressure steam, and compressed air lines. Its black oxide coating provides minimal protection against atmospheric corrosion and serves as an identifier for use in fuel and gas applications. Not rated for potable water use or highly corrosive environments without secondary protection.

Product Specifications

• Material: Carbon steel, ASTM A53 welded
• Nominal Pipe Size: 1/2 inch
• Length: 3-1/2 inches (end-to-end)
• Wall Type: Schedule 40
• End Connections: NPT male x NPT male, per ANSI B1.20.1

Performance Characteristics

• ✅ Threaded Design – Allows for rapid assembly or disassembly during maintenance or retrofit work.
• ✅ System Compatibility – Commonly used with black malleable iron fittings in gas and oil system installations.
• ✅ Operating Pressure – Conforms to pressure ratings of Schedule 40 pipe based on temperature and medium.
• ✅ Field Versatility – Installed in fuel gas, venting, and hydronic heating systems; not intended for potable water.
• ✅ Dimensional Accuracy – Machined to meet industrial tolerance standards for thread fit and alignment.

Installation Guidance

Install using industry-standard pipe wrenches and approved thread sealants (e.g., PTFE tape or pipe dope) to ensure leak-tight performance. Avoid overtightening, which can lead to thread damage or joint failure. Verify compatibility with adjoining pipe materials and components before assembly.

Common Applications

Used across mechanical and plumbing systems where short lengths of pipe are required between threaded fittings. Typical installations include gas furnace tie-ins, boiler manifolds, fuel oil supply lines, and compressed air drops in commercial or industrial settings.

Standards and Compliance

Conforms to ASTM and ANSI standards governing pipe nipples used in mechanical and plumbing applications. Intended for systems that comply with the International Mechanical Code (IMC), NFPA fuel gas standards, and local jurisdictional requirements.

The 1/2" x 3-1/2" black steel nipple provides a durable, code-compliant solution for mechanical connections where weld-free installation is required. It ensures performance under typical system pressures and temperatures in line with Schedule 40 steel specifications.