The B&K Products 521-332HN Black Iron Reducing Coupling is a rugged and dependable fitting designed to connect two female-threaded pipes of differing diameters. Made from black malleable iron, this coupling is engineered for industrial-grade performance and is not intended for potable water systems. Its robust construction and corrosion-resistant properties make it ideal for demanding mechanical and fluid transport applications.

This reducing coupling is commonly used in systems that handle lubricants, oils, greases, liquefied petroleum (LP) gases, natural gases (including nitrogen and oxygen), steam, and diesel. It is also a reliable choice for mechanical and industrial DIY projects. The malleable iron body ensures a tight seal due to the metal’s relative softness, which enhances thread engagement and leak resistance.

Threaded ends conform to ANSI/ASME B1.20.1 standards, ensuring compatibility with standard piping systems. The fitting meets ASTM and ASME standards and is rated for high-pressure applications, performing reliably up to 500 PSI at 150°F.

Key Features & Applications

• Black malleable iron construction for industrial durability.
• 150-lb class malleable fittings for robust performance.
• Rated up to 500 PSI at 150°F, suitable for high-pressure systems.
• Threaded ends comply with ANSI/ASME B1.20.1 standards for secure connections.
• Meets ASTM and ASME standards for quality assurance.
• Ideal for:
  • Lubricant transport
  • Oil and grease systems
  • LP and natural gas lines
  • Steam systems
  • Diesel fuel systems
  • DIY mechanical projects