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

1/8" x 3-1/2" Black Steel Nipple – Threaded Pipe Fitting for Low-Pressure Applications

The 1/8" x 3-1/2" black steel nipple is a straight pipe section with male National Pipe Thread (NPT) ends, used to connect two female-threaded fittings in low- to medium-pressure piping systems. This component is fabricated from welded black steel pipe conforming to ASTM standards for general plumbing, gas, and HVAC applications.

Black steel pipe nipples are commonly specified for systems requiring rigidity, temperature resistance, and structural integrity. Their threaded design facilitates straightforward mechanical joining without the need for welding or flanging in systems not exposed to potable water or corrosive fluids.

Key Product Features

• ✅ Nominal Size: 1/8" NPT
• ✅ Length: 3-1/2" overall
• ✅ Material: Welded black steel pipe (ASTM A53 or equivalent)
• ✅ Thread Type: Male NPT, tapered for mechanical seal compatibility
• ✅ Application: Steam, gas, air, and non-potable water distribution systems

Installation Considerations

For optimal performance, apply thread sealant or PTFE tape to male threads before assembly to minimize leakage risk. Use appropriate torque when tightening to avoid thread damage or over-compression. Always confirm thread engagement depth and fitting alignment per system specifications. This fitting is intended for use in systems rated for non-corrosive, non-potable service where black steel is approved by local code.

Typical Use Cases

Frequently used in gas supply lines, heating systems, compressed air piping, and low-pressure steam systems. Not suitable for potable water service due to the absence of corrosion-resistant coatings. Ideal for retrofits, rigid connections, or structural tie-ins where threaded steel pipe is required.

Compliance and Standards

Conforms to applicable industry specifications for black steel pipe fittings. Verify local mechanical and plumbing code requirements prior to installation in gas or pressure-rated systems.

The 1/8" x 3-1/2" Black Steel Nipple provides a reliable, cost-effective solution for joining threaded components in rigid, low-pressure systems. Its precision threading and durable construction make it suitable for demanding environments where consistent performance is required.