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

1-1/4" x 4-1/2" Black Steel Nipple – Threaded Pipe Fitting for High-Temperature and Low-Pressure Applications

The 1-1/4" x 4-1/2" Black Steel Nipple is a threaded schedule 40 carbon steel fitting used for joining two female-threaded components in mechanical and plumbing systems. Manufactured from welded or seamless black steel pipe, it is suitable for use in oil, gas, steam, and air distribution systems that do not require corrosion-resistant materials.

This nipple features male National Pipe Thread (NPT) ends and is fabricated in accordance with ASTM and ANSI specifications to ensure uniform thread engagement and dimensional reliability. The black finish provides minimal protection against oxidation and is intended for above-ground applications in dry environments.

Product Features

• ✅ Material: Welded or seamless carbon steel pipe, black finish for non-potable use.
• ✅ Threaded Connections: Male NPT x Male NPT, conforming to ANSI B1.20.1 standards.
• ✅ Nominal Size: 1-1/4" diameter x 4-1/2" length (close-cut to ANSI pipe threading practices).
• ✅ Working Pressure: Suitable for non-corrosive fluid and gas systems, with pressure ratings dependent on pipe schedule and temperature range.
• ✅ Temperature Range: Commonly rated for service temperatures up to 650°F depending on media and installation conditions.

Installation and System Compatibility

Black steel nipples must be installed using pipe sealant or PTFE tape on the threads to ensure a secure, leak-resistant joint. Compatible with cast iron, black steel, or galvanized fittings, this component is often used to connect valves, tees, and other distribution fittings in commercial and industrial applications. Do not use in potable water systems unless approved corrosion protection is applied.

Typical Applications

Used in gas lines, HVAC piping, compressed air systems, fire protection risers (in dry systems), and process piping networks where threaded connections are preferred over welding or grooved fittings. Also common in equipment connections where maintenance disassembly may be required.

Technical Insight

Threaded steel nipples provide a rigid, mechanically stable joint and are often preferred in installations where flexibility is not a design requirement. Lengths such as 4-1/2" allow for precise system layout adjustments without unnecessary excess pipe.

The 1-1/4" x 4-1/2" Black Steel Nipple is a standard-grade fitting engineered for service in moderate-temperature, low-to-mid pressure systems. Designed to provide a dependable, threaded connection point in structural, mechanical, and utility piping applications.