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1000/400/500 Series MIL-C-4109 Industrial Interchange Air Swing Coupling, Female Half With Safety Vent, -04 Coupling, 3/8-18 Male NPT

Description & Features

Designed for industrial compressed air systems, the 1000/400/500 Series MIL-C-4109 Industrial Interchange Air Swing Coupling, Female Half With Safety Vent, -04 Coupling, 3/8-18 Male NPT meets dimensional requirements of MIL-C-4109 for broad industrial interchangeability, including compatibility with Aeroquip FD40 Series male halves.

The swing-style connection mechanism allows one-hand coupling by inserting the male half at an angle and swinging to a straight position. A safety vent automatically releases trapped air during disconnection, and the 360° swivel eliminates hose kinking during use. A protective collar reduces the risk of accidental disconnection. The body is constructed of zinc and nickel-plated steel with Buna-N seals as standard. Maximum operating pressure is 360 PSI for this Oetiker model.

The 3/8-18 male NPT thread connection suits a wide range of pneumatic tool and equipment configurations in industrial environments.

SKU: 20500318

Supplier Part Number (MPN): R20500318

Alternate Part Numbers: C1FL21

Specifications

A 2.66	B 0.79	Coupling Size -04	Brand RTC North America Ltd	Brand RTC North America	Pack Size 1.00	UOM EA	Seal Material Buna-N	Supplier Part Number R20500318	Thread 1 3/8-18	Thread Sealant No	Alternate Part Numbers Alternate Part Number C1FL21	Product Weight 0.24 lbs

Similar Products

Model Number	Coupling Size	Thread 1	Seal Material	A	B	Price	Action
20500317 MIL-C-4109 Industrial Air QD	-04	1/4-18	Buna-N	2.66	0.79
20500318 MIL-C-4109 Industrial Air QD	-04	3/8-18	Buna-N	2.66	0.79

Product Questions & Answers (1)

Question by: Janet W on Jul 31, 2025, 2:12 PM

does this thing vent off the air pressure before it fully disconnects, or does it just pop loose all at once?

Answer by: Customer Support on Aug 2, 2025, 6:55 AM

Safe automatic venting of trapped air happens during disconnection before the halves fully separate. That means pressure bleeds off in a controlled way rather than the line releasing all at once. It is a built-in feature of the swing coupling design, not something you have to manage manually.