3/8" Plugs-Ind. Int.-4 Series

Foster Manufacturing 4 Series 3/8" Plug Couplings are designed for rigid mounting that allows a simple push-to-connect operation, constructed of a solid brass body and a steel valve. The "FM" Series are mechanically interchangeable with similar industrial interchange couplings made by other manufacturers and accept plugs that conform to MIL-C4109-F. Plugs used with the "FM" Series are the Industrial Interchange plugs that are found on pages 275, 280, 286, and 288 of the catalog. FM Series 3 and 5 couplers comply with A-A-59439.

  • High flow metal valves.
  • Precision molded seals form a "bubble tight" seal for reliable operation within rated working pressures. Nitrile (Buna-N) seals are standard. EPDM, Viton and Neoprene seals are available as options.
  • Proven ball locking mechanism with large numbers of stainless steel locking balls evenly distribute the load to resist wear and provide positive connections and allow a swiveling action to reduce hose torque.
  • Integral sleeve guard protects the sleeve and resists accidental disconnects for the "SG" series.
  • Knurling and/or grooves on the sleeve provide a gripping surface for ease of operation.
  • Wide range of body sizes, materials, options and end terminations are available to meet specific needs.
  • Accepts Industrial Interchange Plug.

Material: Brass body and socket end, zinc-plated steel sleeve

Specifications Body Size
1/4" 3/8" 1/2" 3/4"
Rated Pressure 300 300 300 300
Temp. Range (Buna-N-Seal) -40° to +250° F
Locking Device 3 Pins 4 Pins 6 Pins 6 pins
Vacuum Data (inches Hg)
--Disconnected (coupler only) Not Recommended
--Connected 27" Hg
Approximate CFM at 100 (psi) 37 70 150 190

Sleeve-Lock Option: Sleeve-Lock feature locks automatic socket against accidental disconnect. To connect, align ball with slot. After connection, rotate sleeve to lock. To disconnect, realign ball with slot and retract sleeve.

Optional Seal Ordering: Buna-N seal is standard. Alternate seals are specified by adding the appropriate suffix to the catalog number. For example, 3003 socket with Heat Adder is 3003H.

Service Construction Seal Temperature Suffix
Air, Vacuum, Grease & Oil Brass & Steel Buna-N -40° to 250° F none
Water Brass & S/S Buna-N 32° to 100° F W
Hot Water Brass & S/S Viton -15° to 400° F HW
Steam Brass Body, Brass Sleeve & Stainless Steel Valve Ethylene Propylene -40° to 300° F S
Heat Brass & Steel Viton -15° to 400° F H
Less valve Brass & Steel Buna-N -40° to 250° F LV
Dill Valve Series 3 Only Brass & Steel Buna-N -40° to 250° F D