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Foster 3 Series Couplers

The Foster 3 Series is the 1/4" body industrial interchange, the most popular air coupler size for shop and industrial systems. This collection includes 3 Series couplers and plugs in brass, steel, and stainless with NPT, hose barb, push-on, and reusable terminations, plus automatic, sleeve guard, ball check, and dust cap options. Filter by thread, material, and coupler or plug to match your line.

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Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass Save 20% Save %
$ 493.00
$ 493.00 - $ 493.00
$ 493.00
$ 394.00
$ 394.00 - $ 394.00
$ 394.00

Foster 14S-3, 1/4" Industrial Plug x 3/8" Male NPT, 3 Series, Free Swivel, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 14S-3 is a Brass/Steel 1/4" industrial plug from the Foster 3 Series — the...

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$ 493.00
$ 493.00 - $ 493.00
$ 493.00
$ 394.00
$ 394.00 - $ 394.00
$ 394.00
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Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass Save 21% Save %
$ 156.00
$ 156.00 - $ 156.00
$ 156.00
$ 124.00
$ 124.00 - $ 124.00
$ 124.00

Foster 10S-3, 1/4" Industrial Plug x 1/4" Male NPT, 3 Series, Free Swivel, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 10S-3 is a Brass/Steel 1/4" industrial plug from the Foster 3 Series — the...

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$ 156.00
$ 156.00 - $ 156.00
$ 156.00
$ 124.00
$ 124.00 - $ 124.00
$ 124.00
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Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass Save 20% Save %
$ 176.00
$ 176.00 - $ 176.00
$ 176.00
$ 140.00
$ 140.00 - $ 140.00
$ 140.00

Foster 12S-3, 1/4" Industrial Plug x 1/8" Male NPT, 3 Series, Free Swivel, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 12S-3 is a Brass/Steel 1/4" industrial plug from the Foster 3 Series — the...

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$ 176.00
$ 176.00 - $ 176.00
$ 176.00
$ 140.00
$ 140.00 - $ 140.00
$ 140.00
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Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass Save 19% Save %
$ 83.00
$ 83.00 - $ 83.00
$ 83.00
$ 67.00
$ 67.00 - $ 67.00
$ 67.00

Foster 71-3, 1/4" Industrial Plug x 3/8" Push-On Hose Stem, 3 Series, Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 71-3 is a Steel 1/4" industrial plug from the Foster 3 Series — the most p...

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$ 83.00
$ 83.00 - $ 83.00
$ 83.00
$ 67.00
$ 67.00 - $ 67.00
$ 67.00
Save 19% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
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$ 93.00
$ 93.00 - $ 93.00
$ 93.00
$ 74.00
$ 74.00 - $ 74.00
$ 74.00

Foster 51-3, 1/4" Industrial Plug x 1/4" Push-On Hose Stem, 3 Series, Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 51-3 is a Steel 1/4" industrial plug from the Foster 3 Series — the most p...

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$ 93.00
$ 93.00 - $ 93.00
$ 93.00
$ 74.00
$ 74.00 - $ 74.00
$ 74.00
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Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
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$ 799.00
$ 799.00 - $ 799.00
$ 799.00
$ 640.00
$ 640.00 - $ 640.00
$ 640.00

Foster 17-3S/S, 1/4" Industrial Plug x 3/8" Hose ID, 3 Series, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 17-3S/S is a 303 Stainless 1/4" industrial plug from the Foster 3 Series —...

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$ 799.00
$ 799.00 - $ 799.00
$ 799.00
$ 640.00
$ 640.00 - $ 640.00
$ 640.00
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Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 19% Save %
$ 131.00
$ 131.00 - $ 131.00
$ 131.00
$ 106.00
$ 106.00 - $ 106.00
$ 106.00

Foster 17-3B, 1/4" Industrial Plug x 3/8" Hose ID, 3 Series, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 17-3B is a Brass 1/4" industrial plug from the Foster 3 Series — the most ...

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$ 131.00
$ 131.00 - $ 131.00
$ 131.00
$ 106.00
$ 106.00 - $ 106.00
$ 106.00
Save 19% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 21% Save %
$ 68.00
$ 68.00 - $ 68.00
$ 68.00
$ 54.00
$ 54.00 - $ 54.00
$ 54.00

Foster 17-3, 1/4" Industrial Plug x 3/8" Hose ID, 3 Series, Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 17-3 is a Steel 1/4" industrial plug from the Foster 3 Series — the most p...

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$ 68.00
$ 68.00 - $ 68.00
$ 68.00
$ 54.00
$ 54.00 - $ 54.00
$ 54.00
Save 21% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
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$ 153.00
$ 153.00 - $ 153.00
$ 153.00
$ 122.00
$ 122.00 - $ 122.00
$ 122.00

Foster 165-3, 1/4" Industrial Plug x 5/16" Hose ID, 3 Series, Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 165-3 is a Steel 1/4" industrial plug from the Foster 3 Series — the most ...

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$ 153.00
$ 153.00 - $ 153.00
$ 153.00
$ 122.00
$ 122.00 - $ 122.00
$ 122.00
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Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
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$ 144.00
$ 144.00 - $ 144.00
$ 144.00
$ 115.00
$ 115.00 - $ 115.00
$ 115.00

Foster 16-3B, 1/4" Industrial Plug x 1/4" Hose ID, 3 Series, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 16-3B is a Brass 1/4" industrial plug from the Foster 3 Series — the most ...

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$ 144.00
$ 144.00 - $ 144.00
$ 144.00
$ 115.00
$ 115.00 - $ 115.00
$ 115.00
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Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 61.00
$ 61.00 - $ 61.00
$ 61.00
$ 49.00
$ 49.00 - $ 49.00
$ 49.00

Foster 16-3, 1/4" Industrial Plug x 1/4" Hose ID, 3 Series, Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 16-3 is a Steel 1/4" industrial plug from the Foster 3 Series — the most p...

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$ 61.00
$ 61.00 - $ 61.00
$ 61.00
$ 49.00
$ 49.00 - $ 49.00
$ 49.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 208.00
$ 208.00 - $ 208.00
$ 208.00
$ 167.00
$ 167.00 - $ 167.00
$ 167.00

Foster 14-3GB, 1/4" Industrial Plug x 3/8" Male NPT, 3 Series, Ball Check, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 14-3GB is a Brass 1/4" industrial plug from the Foster 3 Series — the most...

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$ 208.00
$ 208.00 - $ 208.00
$ 208.00
$ 167.00
$ 167.00 - $ 167.00
$ 167.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 169.00
$ 169.00 - $ 169.00
$ 169.00
$ 135.00
$ 135.00 - $ 135.00
$ 135.00

Foster 14-3B, 1/4" Industrial Plug x 3/8" Male NPT, 3 Series, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 14-3B is a Brass 1/4" industrial plug from the Foster 3 Series — the most ...

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$ 169.00
$ 169.00 - $ 169.00
$ 169.00
$ 135.00
$ 135.00 - $ 135.00
$ 135.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 21% Save %
$ 68.00
$ 68.00 - $ 68.00
$ 68.00
$ 54.00
$ 54.00 - $ 54.00
$ 54.00

Foster 14-3, 1/4" Industrial Plug x 3/8" Male NPT, 3 Series, Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 14-3 is a Steel 1/4" industrial plug from the Foster 3 Series — the most p...

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$ 68.00
$ 68.00 - $ 68.00
$ 68.00
$ 54.00
$ 54.00 - $ 54.00
$ 54.00
Save 21% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 204.00
$ 204.00 - $ 204.00
$ 204.00
$ 163.00
$ 163.00 - $ 163.00
$ 163.00

Foster 10-3GS/S, 1/4" Industrial Plug x 1/4" Male NPT, 3 Series, Ball Check, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 10-3GS/S is a 303 Stainless 1/4" industrial plug from the Foster 3 Series ...

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$ 204.00
$ 204.00 - $ 204.00
$ 204.00
$ 163.00
$ 163.00 - $ 163.00
$ 163.00
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Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 153.00
$ 153.00 - $ 153.00
$ 153.00
$ 122.00
$ 122.00 - $ 122.00
$ 122.00

Foster 10-3GS, 1/4" Industrial Plug x 1/4" Male NPT, 3 Series, Ball Check, Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 10-3GS is a Steel 1/4" industrial plug from the Foster 3 Series — the most...

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$ 153.00
$ 153.00 - $ 153.00
$ 153.00
$ 122.00
$ 122.00 - $ 122.00
$ 122.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 19% Save %
$ 124.00
$ 124.00 - $ 124.00
$ 124.00
$ 101.00
$ 101.00 - $ 101.00
$ 101.00

Foster 10-3GB, 1/4" Industrial Plug x 1/4" Male NPT, 3 Series, Ball Check, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 10-3GB is a Brass 1/4" industrial plug from the Foster 3 Series — the most...

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$ 124.00
$ 124.00 - $ 124.00
$ 124.00
$ 101.00
$ 101.00 - $ 101.00
$ 101.00
Save 19% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
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$ 90.00
$ 90.00 - $ 90.00
$ 90.00
$ 72.00
$ 72.00 - $ 72.00
$ 72.00

Foster 10-3G, 1/4" Industrial Plug x 1/4" Male NPT, 3 Series, Ball Check, Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 10-3G is a Steel 1/4" industrial plug from the Foster 3 Series — the most ...

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$ 90.00
$ 90.00 - $ 90.00
$ 90.00
$ 72.00
$ 72.00 - $ 72.00
$ 72.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 226.00
$ 226.00 - $ 226.00
$ 226.00
$ 181.00
$ 181.00 - $ 181.00
$ 181.00

Foster 10-3D, 1/4" Industrial Plug x 1/4" Male NPT, 3 Series, Dill Valve, Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 10-3D is a Steel 1/4" industrial plug from the Foster 3 Series — the most ...

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$ 226.00
$ 226.00 - $ 226.00
$ 226.00
$ 181.00
$ 181.00 - $ 181.00
$ 181.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 170.00
$ 170.00 - $ 170.00
$ 170.00
$ 136.00
$ 136.00 - $ 136.00
$ 136.00

Foster 10-3S/S, 1/4" Industrial Plug x 1/4" Male NPT, 3 Series, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 10-3S/S is a 303 Stainless 1/4" industrial plug from the Foster 3 Series —...

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$ 170.00
$ 170.00 - $ 170.00
$ 170.00
$ 136.00
$ 136.00 - $ 136.00
$ 136.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 18% Save %
$ 68.00
$ 68.00 - $ 68.00
$ 68.00
$ 56.00
$ 56.00 - $ 56.00
$ 56.00

Foster 10-3B, 1/4" Industrial Plug x 1/4" Male NPT, 3 Series, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 10-3B is a Brass 1/4" industrial plug from the Foster 3 Series — the most ...

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$ 68.00
$ 68.00 - $ 68.00
$ 68.00
$ 56.00
$ 56.00 - $ 56.00
$ 56.00
Save 18% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 21% Save %
$ 43.00
$ 43.00 - $ 43.00
$ 43.00
$ 34.00
$ 34.00 - $ 34.00
$ 34.00

Foster 10-3, 1/4" Industrial Plug x 1/4" Male NPT, 3 Series, Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 10-3 is a Steel 1/4" industrial plug from the Foster 3 Series — the most p...

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$ 43.00
$ 43.00 - $ 43.00
$ 43.00
$ 34.00
$ 34.00 - $ 34.00
$ 34.00
Save 21% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 224.00
$ 224.00 - $ 224.00
$ 224.00
$ 179.00
$ 179.00 - $ 179.00
$ 179.00

Foster 12-3S/S, 1/4" Industrial Plug x 1/8" Male NPT, 3 Series, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 12-3S/S is a 303 Stainless 1/4" industrial plug from the Foster 3 Series —...

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$ 224.00
$ 224.00 - $ 224.00
$ 224.00
$ 179.00
$ 179.00 - $ 179.00
$ 179.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 90.00
$ 90.00 - $ 90.00
$ 90.00
$ 72.00
$ 72.00 - $ 72.00
$ 72.00

Foster 12-3B, 1/4" Industrial Plug x 1/8" Male NPT, 3 Series, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 12-3B is a Brass 1/4" industrial plug from the Foster 3 Series — the most ...

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$ 90.00
$ 90.00 - $ 90.00
$ 90.00
$ 72.00
$ 72.00 - $ 72.00
$ 72.00
Save 20% Save %

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