Black Steel Fittings - Unions

Complete your gas, fire suppression, or industrial piping system with black steel malleable iron fittings — the standard choice wherever threaded steel pipe connections are required. Built tough for high-pressure and high-temperature applications, black steel fittings are a staple on every commercial and residential gas line rough-in.

What Are Black Steel Fittings?

Black steel fittings are malleable iron threaded fittings with a black oxide finish (no galvanizing). They are designed for use with black steel pipe on natural gas, propane, fire sprinkler, steam, and compressed air systems. The black finish distinguishes them from galvanized fittings, which are not suitable for gas service.

Fitting Types Available

• Elbows — 90° and 45° in street and standard configurations
• Tees — straight and reducing tees for branch connections
• Couplings — standard and reducing for inline connections
• Nipples — close, short, and long in common sizes
• Caps & Plugs — for capping open ends and pressure testing
• Unions — for connections that may need to be broken and remade
• Bushings — for reducing threaded connections

Common Applications

• Natural gas and propane distribution lines
• Fire suppression and sprinkler systems
• Steam and high-temperature piping
• Compressed air systems
• Industrial process piping

Key Specs

• Material: Malleable iron with black oxide finish
• Thread standard: NPT (National Pipe Thread)
• Pressure rated: 150 lb class (standard) — suitable for most gas and steam applications
• Sizes: 1/4" through 2" (common stock sizes)
• Not for use with galvanized pipe on gas lines — always use black fittings with black pipe for gas service

Same-day pickup available at AC Construction Depot in Pineville, NC. Serving plumbers, pipefitters, and contractors across the greater Charlotte area. Call us at 704-835-1086 to confirm availability on specific sizes and configurations before your trip.