API Certified Permanently Attached Petroleum 520-H Female Coupling

API Certified Permanently Attached Petroleum 520-H Female Coupling

Part Number H5221-A-BU
Material Brass
Thread NPSH
Hose Size 1-1/4"
Optional Pkg/Box Qty 48
Weight Lb 0.6200


  • Recommended for discharge and suction service. Commonly used in the transfer of fuel to homes, airplanes, ships, etc.


  • May also be used with Internally expanding Permanent Couplings- Scovill Style
  • Designed for internal expansion only.


  • API certified, tested and compliant with API 1529 6th edition


  • Female has octagonal facets for tightening with a wrench
  • The stem is expanded to nominal ID of hose for a rigid, uniform, full-flow area.
  • Couplings are compact, light and streamlined to eliminate catching on curbs and shrubs.
  • Couplings are pre-lubricated for assembly.


  • Stems are machined from bar stock or solid brass forgings


  • The working pressure of the 520-H fitting varies with the size of the fitting, the size and construction of the hose and the media being conveyed.
  • Coupling procedures, ferrule recommendations and API test data are available upon request, please contact Dixon.
  • Hand and electrically operated installation equipment is available. Consult Dixon for pricing and availability.

Safety notes

  • Do not interchange with other manufacturer's fittings.
  • Designed for internal expansion only.
  • Dixon Holedall stems and ferrules are specifically designed to be used together as a coupling system.
  • Do not use a wrench or vice on ferrule
  • Holedall couplings, regardless of coupling style, are never to be used for steam service at any pressure.
  • Holedall fittings are not to be used with cable reinforced high-pressure hose, 4 or 6 braid wire hydraulic hose or any other service not listed in the recommendations. Consult Dixon for recommendations on usage.
  • Strict adherence to ferrule OD range (Internally Expanded) for each hose end to be assembled is essential for satisfactory performance.
  • Hose service working pressure (including surges and spikes) is never to exceed the maximum recommended working pressure for the fitting. The assembly's (hose + coupling) maximum working pressure is the lesser of the hose rated working pressure or the coupling rated working pressure.
  • Media being transported through the hose should be compatible with the stem material. Compatibility of ferrule material with the environment in which it will be used is recommended. Consult the Compatibility Chart or the Dixon factory for material compatibility.
  • For applications other than the ones list, please consult Dixon.


Catalog Page

Dimensional Specifications

Interactive Resources


Related Products


Stock Availability