4 inch x 5-1/2 inch Black Steel Nipple

4" x 5-1/2" Black Steel Nipple – Threaded Schedule 40 Connector for Gas, Water, and Air Systems

The 4" x 5-1/2" Black Steel Nipple is a threaded pipe segment used to connect two female-threaded fittings in mechanical and plumbing systems. Fabricated from welded Schedule 40 black steel pipe, this nipple is designed for use in non-potable water, gas, oil, and air distribution systems operating under moderate pressure conditions.

Manufactured in compliance with ASTM A53 and threaded to ANSI B1.20.1 standards, this fitting offers uniform wall thickness, straightness, and thread consistency, supporting secure, leak-resistant installations in both new construction and retrofit applications.

Technical Specifications

• Material: Carbon Steel with black coating (ASTM A53 Type E or S, Grade A or B)
• Size: 4" nominal pipe diameter x 5-1/2" overall length
• Wall Thickness: Schedule 40
• Connection Type: Male NPT threads on both ends
• Thread Standard: ANSI B1.20.1 (National Pipe Taper)
• End Finish: Threaded & chamfered; plain end available upon request

Installation Guidelines

Install using appropriate pipe sealant or PTFE thread tape rated for system media. Tighten with a pipe wrench, ensuring not to overtighten and damage threads. Align the nipple properly to reduce stress at connection points. Final assembly should be pressure-tested per applicable code or project specifications.

Applications

Used in commercial, industrial, and mechanical piping systems to connect equipment or extend existing pipe runs. Commonly applied in fuel gas piping, compressed air systems, fire sprinkler mains (non-galvanized), and process lines where corrosion resistance from paint or galvanization is not required by code.

Material Characteristics

Black steel provides a clean, corrosion-resistant surface suitable for indoor or protected environments. Its strength and machinability make it a common choice in mechanical systems requiring threaded steel pipe. Not recommended for use in potable water systems unless otherwise coated or lined.