A complete coupling consists of a plug and a socket (both sold separately or in a set) that connect and disconnect quickly. Use them if you need frequent access to a line. They are also known as industrial interchange couplings. All Industrial plugs are compatible with any of the Industrial sockets of the same coupling size, regardless of the pipe size or barbed hose ID.

Steel is stronger and more durable than other metals. Zinc-plated steel has fair corrosion resistance and should be used primarily in dry environments. Chrome-plated steel has fair corrosion resistance and has a bright, shiny appearance. Nickel-plated steel has good corrosion resistance. Aluminum is lighter in weight than other metals and has good corrosion resistance. Brass is softer than other metals, so it’s easier to thread together. It has good corrosion resistance. Nickel-plated brass has better corrosion resistance than unplated brass. Nylon has good corrosion resistance, is nonmarring, and won’t scratch delicate surfaces. 303 stainless steel has very good corrosion resistance, so it’s the best choice for high-humidity environments.

NPTF (Dryseal) threads are compatible with NPT threads.

Note: To ensure a correct fit, make sure that the plug and socket have the same coupling size.Coupling
Size Lg. Dia. Pipe
Sizeclick to learn more about Specifications Met Each
Zinc-Plated Steel
1/8 1/8" 1/4" 1/8 __ 6534K841 $2.97
1/8 1/8" 1/4" 1/4 __ 6534K842 4.86
1/4 3/16" 5/16" 1/8 Fed. Spec. A-A-59439, ISO 6150/B 6534K19 2.29
1/4 3/16" 5/16" 1/4 Fed. Spec. A-A-59439, ISO 6150/B 6534K46 1.41
1/4 3/16" 5/16" 3/8 Fed. Spec. A-A-59439, ISO 6150/B 6534K47 2.18
3/8 5/16" 7/16" 1/8 ISO 6150/B 6534K843 10.83
3/8 5/16" 7/16" 1/4 ISO 6150/B 6534K71 3.44
3/8 5/16" 7/16" 3/8 ISO 6150/B 6534K72 5.62
3/8 5/16" 7/16" 1/2 ISO 6150/B 6534K73 5.71
1/2 3/8" 9/16" 1/4 Fed. Spec. A-A-59439, ISO 6150/B 6534K111 5.64
1/2 3/8" 9/16" 3/8 Fed. Spec. A-A-59439, ISO 6150/B 6534K42 3.97
1/2 3/8" 9/16" 1/2 Fed. Spec. A-A-59439, ISO 6150/B 6534K43 4.97
1/2 3/8" 9/16" 3/4 Fed. Spec. A-A-59439, ISO 6150/B 6534K44 6.03
3/4 5/16" 13/16" 1/2 __ 6534K112 13.35
3/4 5/16" 13/16" 3/4 __ 6534K49 8.03
3/4 5/16" 13/16" 1 __ 6534K61 18.20
Plug Tip
Coupling
Size Lg. Dia. Pipe
Size Specifications Met Each
Nickel-Plated Steel
1/4 3/16" 5/16" 1/4 Fed. Spec. A-A-59439, ISO 6150/B 6050T14 $4.68
1/4 3/16" 5/16" 3/8 Fed. Spec. A-A-59439, ISO 6150/B 6050T34 9.04
3/8 5/16" 7/16" 1/4 __ 6050T17 9.78
Brass
1/8 1/8" 1/4" 1/8 __ 1077T111 3.04
1/4 3/16" 5/16" 1/8 Fed. Spec. A-A-59439, ISO 6150/B 1077T112 3.55
1/4 3/16" 5/16" 1/4 Fed. Spec. A-A-59439, ISO 6150/B 1077T17 1.82
1/4 3/16" 5/16" 3/8 Fed. Spec. A-A-59439, ISO 6150/B 1077T18 3.20
3/8 5/16" 7/16" 3/8 Fed. Spec. A-A-59439, ISO 6150/B 1077T21 5.33
1/2 3/8" 9/16" 1/4 Fed. Spec. A-A-59439, ISO 6150/B 1077T42 6.05
1/2 3/8" 9/16" 3/8 Fed. Spec. A-A-59439, ISO 6150/B 1077T113 11.31
1/2 3/8" 9/16" 1/2 Fed. Spec. A-A-59439, ISO 6150/B 1077T23 5.90
1/2 3/8" 9/16" 3/4 Fed. Spec. A-A-59439, ISO 6150/B 1077T31 8.95
3/4 5/16" 13/16" 3/4 ISO 6150/B 1077T43 10.71
Plug Tip
Coupling
Size Lg. Dia. Pipe
Size Specifications Met Each
303 Stainless Steel
1/8 1/8" 1/4" 1/8 __ 6718K45 $5.69
1/4 3/16" 5/16" 1/8 Fed. Spec. A-A-59439, ISO 6150/B 6718K76 11.21
1/4 3/16" 5/16" 1/4 Fed. Spec. A-A-59439, ISO 6150/B 6718K26 6.51
1/4 3/16" 5/16" 3/8 Fed. Spec. A-A-59439, ISO 6150/B 6718K56 8.07
3/8 5/16" 7/16" 1/4 ISO 6150/B 6718K46 9.76
3/8 5/16" 7/16" 3/8 ISO 6150/B 6718K28 13.28
1/2 3/8" 9/16" 1/4 Fed. Spec. A-A-59439, ISO 6150/B 6718K111 27.67
1/2 3/8" 9/16" 3/8 Fed. Spec. A-A-59439, ISO 6150/B 6718K113 9.83
1/2 3/8" 9/16" 1/2 Fed. Spec. A-A-59439, ISO 6150/B 6718K31 18.79
1/2 3/8" 9/16" 3/4 Fed. Spec. A-A-59439, ISO 6150/B 6718K47 19.53