3/8 inch x 1/4 inch Black Iron Reducing Coupling Female x Female

$2.12
- +
In stock
2 Available At My Branch
10 Available At All US Supply Locations
Brand
Brand May Vary
Part Number
521-321
SKU
7726

Black Iron Reducing Coupling – 3/8" x 1/4" for Threaded Pipe Size Transitions

The 3/8" x 1/4" Black Iron Reducing Coupling provides a dependable solution for reducing nominal pipe sizes in threaded pipe systems. Designed for mechanical strength and dimensional precision, this fitting is suitable for air, gas, oil, and steam lines where pressure and temperature demands are significant.

Fabricated from black malleable iron, this coupling features internal threads (FIP x FIP) that conform to industry threading standards, allowing for straightforward integration with standard schedule 40 black steel pipe. The black finish is intended for applications where corrosion resistance coatings are not required, such as dry-piping environments and indoor mechanical systems.

Key Attributes for Jobsite Performance

  • Thread Precision: Machined threads ensure consistent engagement and secure torque during assembly.
  • Pressure-Ready Design: Suitable for systems operating under moderate to high internal pressures.
  • Material Strength: Manufactured from ASTM A197/A197M-compliant black malleable iron for tensile durability.
  • Dimensional Accuracy: Tapered thread design enables tighter sealing surfaces, minimizing the need for retorquing.
  • Standards Compliance: Compatible with ASME B16.3 and B16.14 fittings and threading specifications.

Installation Parameters

For optimal installation, apply approved thread sealant or PTFE tape to male threads before engagement. Avoid over-tightening to reduce risk of cracking or galling. Use a pipe wrench to maintain alignment during tightening. This fitting should be installed according to local mechanical and fuel gas code requirements where applicable.

Applications and System Integration

This reducing coupling is frequently used in HVAC systems, mechanical rooms, compressed air piping, and fuel gas infrastructure where a transition from 3/8" to 1/4" nominal size is required. Not intended for use with potable water systems unless permitted by local code.

Material Insight

Black iron is selected for its performance under high temperature and pressure applications. Its carbon-rich composition and threaded integrity make it well-suited for steam and gas distribution in closed piping networks.

Technical Specifications

  • Nominal Size: 3/8 inch x 1/4 inch
  • Connection: FIP x FIP (Female Iron Pipe Threads)
  • Material: Black Malleable Iron
  • Standards: Meets or exceeds ASTM A197, ASME B16.3

Designed for pressure systems requiring dimensional transitions and structural reliability, the 3/8" x 1/4" Black Iron Reducing Coupling meets the practical requirements of commercial, industrial, and retrofit applications.

Specifications

Specifications
Weight 0.110000
Brand Brand May Vary
ADA Compliance No
Height 1.2
Length 0.95
Width 0.95
End Style Female x Female
Side A 3/8"
Side B 1/4"
Fitting Type Reducing Coupling
Item Type Coupling
MPN 521-321
Material Black Iron
Product Family Fittings
Item Returns This item can be returned
Features