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

1-1/2" x 3-1/2" Black Steel Schedule 40 Nipple for Low-Pressure Piping Systems

The 1-1/2 inch x 3-1/2 inch Black Steel Nipple is a Schedule 40 pipe fitting designed to extend runs, connect components, or facilitate changes in pipe direction within threaded piping systems. Commonly used in steam, air, gas, and hydronic heating systems, this nipple is fabricated from seamless black steel pipe and features NPT threads on both ends.

Performance Characteristics

This fitting is manufactured to meet ASTM and ANSI standards for pressure-rated threaded steel components. It is suitable for use in non-potable systems and is commonly installed in mechanical rooms, HVAC piping, fire protection headers (where allowed), and industrial process lines.

• ✅ Threaded Male Ends Standard ANSI B1.20.1 NPT threads for compatibility with cast iron, steel, and malleable fittings.
• ✅ Seamless Construction Manufactured from seamless carbon steel pipe for structural integrity and pressure retention.
• ✅ Black Finish Supplied with a black oxide coating; suitable for above-ground applications in dry systems.
• ✅ Temperature Tolerance Suitable for use in high-temperature piping systems up to rated service limits.
• ✅ Cut Length: 3-1/2" overall; includes thread engagement length on both ends.

Technical Specifications

• Material: Carbon Steel (ASTM A53/A106 Grade B)
• Finish: Black (uncoated; not for potable water)
• Nominal Size: 1-1/2 Inch
• Length: 3-1/2 Inch (overall including thread)
• Thread Type: NPT Male x NPT Male
• Wall Thickness: Schedule 40

Installation Considerations

Use with compatible threaded fittings in accordance with the system pressure rating and temperature exposure. Apply approved pipe joint compound or PTFE tape on threads to ensure leak-tight connections. Torque to spec using standard pipe wrenches; avoid over-tightening which may crack adjacent fittings or distort threads.

Typical Applications

This black steel nipple is widely used in natural gas distribution, air compressor lines, boiler loop piping, and industrial piping where corrosion resistance is not a primary concern. Not recommended for potable water or buried installations without external coating or wrap.

Material Note

Black steel is selected for its machinability and strength under pressure. Unlike galvanized pipe, it is suitable for systems that do not require corrosion-resistant coatings or involve closed-loop hydronic environments.

The 1-1/2" x 3-1/2" Black Steel Nipple is a reliable joining component for threaded steel pipe systems requiring short-length extensions or precision spacing between fittings. Specify for assemblies where dimensional accuracy and mechanical integrity are required under pressure or heat exposure.