3/8 inch x 3 inch Black Steel Nipple

3/8" x 3" Black Steel Pipe Nipple – Schedule 40, Threaded Both Ends

The 3/8" x 3" black steel pipe nipple is a Schedule 40 fitting used for joining two female-threaded components in mechanical and low- to medium-pressure piping systems. It is manufactured from carbon steel pipe conforming to ASTM A53 specifications and features NPT (National Pipe Taper) threads per ANSI B1.20.1 on both ends.

This nipple is designed for use in systems that require a rigid, threaded connection in air, water, oil, steam, or gas service lines. It is not intended for use with potable water unless otherwise permitted by local code. The black oxide finish provides temporary corrosion resistance and is suitable for indoor or dry installations.

Product Specifications

• Nominal Size: 3/8"
• Length: 3" overall
• Material: Welded or seamless black steel (ASTM A53)
• Thread Type: Male NPT x Male NPT (ANSI B1.20.1)
• Wall Thickness: Schedule 40

Performance and Installation

• ✅ Pressure Rating: Suitable for pressure ranges consistent with Schedule 40 piping, dependent on temperature and application
• ✅ Installation: Apply thread sealant or PTFE tape before tightening to prevent leaks
• ✅ Compatibility: Used with threaded black steel fittings, valves, and couplings
• ✅ Common Environments: Found in HVAC systems, industrial process piping, fire protection headers (non-potable), and gas distribution networks

Application Notes

This nipple is used in threaded piping systems where sections must be joined or extended. The 3" length allows for utility spacing between components in confined or fixed layouts. Typical installations include boiler rooms, gas appliance branches, pump manifolds, and air compressor lines. Suitable for above-ground service only unless corrosion mitigation is provided.

Material Insight

Black steel pipe nipples are preferred for their mechanical strength and ease of threading. While the black finish provides limited corrosion resistance, additional protective coatings or wraps may be required in damp or outdoor conditions. Always verify system compatibility and pressure ratings before installation.