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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 %
$ 574.00
$ 574.00 - $ 574.00
$ 574.00
$ 460.00
$ 460.00 - $ 460.00
$ 460.00

Foster SC7-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 5/16" ID x 5/8" OD, 3 Series, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SC7-3 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series — ...

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$ 574.00
$ 574.00 - $ 574.00
$ 574.00
$ 460.00
$ 460.00 - $ 460.00
$ 460.00
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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 %
$ 566.00
$ 566.00 - $ 566.00
$ 566.00
$ 453.00
$ 453.00 - $ 453.00
$ 453.00

Foster BLSC5-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 5/16" ID x 9/16" OD, 3 Series, Ball Lock, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BLSC5-3 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series ...

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$ 566.00
$ 566.00 - $ 566.00
$ 566.00
$ 453.00
$ 453.00 - $ 453.00
$ 453.00
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 %
$ 567.00
$ 567.00 - $ 567.00
$ 567.00
$ 454.00
$ 454.00 - $ 454.00
$ 454.00

Foster SC5-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 5/16" ID x 9/16" OD, 3 Series, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SC5-3 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series — ...

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$ 567.00
$ 567.00 - $ 567.00
$ 567.00
$ 454.00
$ 454.00 - $ 454.00
$ 454.00
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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 %
$ 465.00
$ 465.00 - $ 465.00
$ 465.00
$ 373.00
$ 373.00 - $ 373.00
$ 373.00

Foster BLSB7-3W, 1/4" Industrial Coupler x Reusable Hose Fitting, 1/4" ID x 5/8" OD, 3 Series, Ball Lock, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BLSB7-3W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — ...

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$ 465.00
$ 465.00 - $ 465.00
$ 465.00
$ 373.00
$ 373.00 - $ 373.00
$ 373.00
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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 %
$ 400.00
$ 400.00 - $ 400.00
$ 400.00
$ 320.00
$ 320.00 - $ 320.00
$ 320.00

Foster SB7-3W, 1/4" Industrial Coupler x Reusable Hose Fitting, 1/4" ID x 5/8" OD, 3 Series, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SB7-3W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — th...

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$ 400.00
$ 400.00 - $ 400.00
$ 400.00
$ 320.00
$ 320.00 - $ 320.00
$ 320.00
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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 %
$ 1,173.00
$ 1,173.00 - $ 1,173.00
$ 1,173.00
$ 938.00
$ 938.00 - $ 938.00
$ 938.00

Foster BLSB7-3S/S, 1/4" Industrial Coupler x Reusable Hose Fitting, 1/4" ID x 5/8" OD, 3 Series, Ball Lock, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BLSB7-3S/S is a 303 Stainless 1/4" industrial coupler from the Foster 3 Se...

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$ 1,173.00
$ 1,173.00 - $ 1,173.00
$ 1,173.00
$ 938.00
$ 938.00 - $ 938.00
$ 938.00
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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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$ 1,105.00
$ 1,105.00 - $ 1,105.00
$ 1,105.00
$ 884.00
$ 884.00 - $ 884.00
$ 884.00

Foster SB7-3S/S, 1/4" Industrial Coupler x Reusable Hose Fitting, 1/4" ID x 5/8" OD, 3 Series, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SB7-3S/S is a 303 Stainless 1/4" industrial coupler from the Foster 3 Seri...

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$ 1,105.00
$ 1,105.00 - $ 1,105.00
$ 1,105.00
$ 884.00
$ 884.00 - $ 884.00
$ 884.00
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 %
$ 367.00
$ 367.00 - $ 367.00
$ 367.00
$ 294.00
$ 294.00 - $ 294.00
$ 294.00

Foster BLSB7-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 1/4" ID x 5/8" OD, 3 Series, Ball Lock, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BLSB7-3 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series ...

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$ 367.00
$ 367.00 - $ 367.00
$ 367.00
$ 294.00
$ 294.00 - $ 294.00
$ 294.00
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 %
$ 340.00
$ 340.00 - $ 340.00
$ 340.00
$ 272.00
$ 272.00 - $ 272.00
$ 272.00

Foster SB7-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 1/4" ID x 5/8" OD, 3 Series, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SB7-3 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series — ...

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$ 340.00
$ 340.00 - $ 340.00
$ 340.00
$ 272.00
$ 272.00 - $ 272.00
$ 272.00
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 %
$ 494.00
$ 494.00 - $ 494.00
$ 494.00
$ 395.00
$ 395.00 - $ 395.00
$ 395.00

Foster BLSB5-3W, 1/4" Industrial Coupler x Reusable Hose Fitting, 1/4" ID x 9/16" OD, 3 Series, Ball Lock, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BLSB5-3W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — ...

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$ 494.00
$ 494.00 - $ 494.00
$ 494.00
$ 395.00
$ 395.00 - $ 395.00
$ 395.00
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 %
$ 385.00
$ 385.00 - $ 385.00
$ 385.00
$ 306.00
$ 306.00 - $ 306.00
$ 306.00

Foster BLSB5-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 1/4" ID x 9/16" OD, 3 Series, Ball Lock, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BLSB5-3 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series ...

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$ 385.00
$ 385.00 - $ 385.00
$ 385.00
$ 306.00
$ 306.00 - $ 306.00
$ 306.00
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 %
$ 367.00
$ 367.00 - $ 367.00
$ 367.00
$ 294.00
$ 294.00 - $ 294.00
$ 294.00

Foster SB5-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 1/4" ID x 9/16" OD, 3 Series, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SB5-3 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series — ...

View full details
$ 367.00
$ 367.00 - $ 367.00
$ 367.00
$ 294.00
$ 294.00 - $ 294.00
$ 294.00
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 %
$ 413.00
$ 413.00 - $ 413.00
$ 413.00
$ 331.00
$ 331.00 - $ 331.00
$ 331.00

Foster SB3-3W, 1/4" Industrial Coupler x Reusable Hose Fitting, 1/4" ID x 1/2" OD, 3 Series, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SB3-3W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — th...

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$ 413.00
$ 413.00 - $ 413.00
$ 413.00
$ 331.00
$ 331.00 - $ 331.00
$ 331.00
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 %
$ 1,910.00
$ 1,910.00 - $ 1,910.00
$ 1,910.00
$ 1,529.00
$ 1,529.00 - $ 1,529.00
$ 1,529.00

Foster SB3-3S/S, 1/4" Industrial Coupler x Reusable Hose Fitting, 1/4" ID x 1/2" OD, 3 Series, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SB3-3S/S is a 303 Stainless 1/4" industrial coupler from the Foster 3 Seri...

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$ 1,910.00
$ 1,910.00 - $ 1,910.00
$ 1,910.00
$ 1,529.00
$ 1,529.00 - $ 1,529.00
$ 1,529.00
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 %
$ 458.00
$ 458.00 - $ 458.00
$ 458.00
$ 366.00
$ 366.00 - $ 366.00
$ 366.00

Foster BLSB3-3W, 1/4" Industrial Coupler x Reusable Hose Fitting, 1/4" ID x 1/2" OD, 3 Series, Ball Lock, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BLSB3-3W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — ...

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$ 458.00
$ 458.00 - $ 458.00
$ 458.00
$ 366.00
$ 366.00 - $ 366.00
$ 366.00
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 %
$ 345.00
$ 345.00 - $ 345.00
$ 345.00
$ 275.00
$ 275.00 - $ 275.00
$ 275.00

Foster 3703W, 1/4" Industrial Coupler x 3/8" Hose ID, 3 Series, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3703W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — the...

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$ 345.00
$ 345.00 - $ 345.00
$ 345.00
$ 275.00
$ 275.00 - $ 275.00
$ 275.00
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 %
$ 1,258.00
$ 1,258.00 - $ 1,258.00
$ 1,258.00
$ 1,006.00
$ 1,006.00 - $ 1,006.00
$ 1,006.00

Foster BL3703S/S, 1/4" Industrial Coupler x 3/8" Hose ID, 3 Series, Ball Lock, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BL3703S/S is a 303 Stainless 1/4" industrial coupler from the Foster 3 Ser...

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$ 1,258.00
$ 1,258.00 - $ 1,258.00
$ 1,258.00
$ 1,006.00
$ 1,006.00 - $ 1,006.00
$ 1,006.00
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 %
$ 1,197.00
$ 1,197.00 - $ 1,197.00
$ 1,197.00
$ 959.00
$ 959.00 - $ 959.00
$ 959.00

Foster 3703S/S, 1/4" Industrial Coupler x 3/8" Hose ID, 3 Series, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3703S/S is a 303 Stainless 1/4" industrial coupler from the Foster 3 Serie...

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$ 1,197.00
$ 1,197.00 - $ 1,197.00
$ 1,197.00
$ 959.00
$ 959.00 - $ 959.00
$ 959.00
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 %
$ 341.00
$ 341.00 - $ 341.00
$ 341.00
$ 273.00
$ 273.00 - $ 273.00
$ 273.00

Foster 3703S, 1/4" Industrial Coupler x 3/8" Hose ID, 3 Series, Steam/EPDM, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3703S is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — the...

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$ 341.00
$ 341.00 - $ 341.00
$ 341.00
$ 273.00
$ 273.00 - $ 273.00
$ 273.00
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 %
$ 308.00
$ 308.00 - $ 308.00
$ 308.00
$ 247.00
$ 247.00 - $ 247.00
$ 247.00

Foster BL3703, 1/4" Industrial Coupler x 3/8" Hose ID, 3 Series, Ball Lock, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BL3703 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series —...

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$ 308.00
$ 308.00 - $ 308.00
$ 308.00
$ 247.00
$ 247.00 - $ 247.00
$ 247.00
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 %
$ 273.00
$ 273.00 - $ 273.00
$ 273.00
$ 220.00
$ 220.00 - $ 220.00
$ 220.00

Foster 3703, 1/4" Industrial Coupler x 3/8" Hose ID, 3 Series, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3703 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series — t...

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$ 273.00
$ 273.00 - $ 273.00
$ 273.00
$ 220.00
$ 220.00 - $ 220.00
$ 220.00
Save 19% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
Save 20% Save %
$ 305.00
$ 305.00 - $ 305.00
$ 305.00
$ 244.00
$ 244.00 - $ 244.00
$ 244.00

Foster BL3653, 1/4" Industrial Coupler x 5/16" Hose ID, 3 Series, Ball Lock, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BL3653 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series —...

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$ 305.00
$ 305.00 - $ 305.00
$ 305.00
$ 244.00
$ 244.00 - $ 244.00
$ 244.00
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 %
$ 298.00
$ 298.00 - $ 298.00
$ 298.00
$ 239.00
$ 239.00 - $ 239.00
$ 239.00

Foster 3653, 1/4" Industrial Coupler x 5/16" Hose ID, 3 Series, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3653 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series — t...

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$ 298.00
$ 298.00 - $ 298.00
$ 298.00
$ 239.00
$ 239.00 - $ 239.00
$ 239.00
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 %
$ 308.00
$ 308.00 - $ 308.00
$ 308.00
$ 247.00
$ 247.00 - $ 247.00
$ 247.00

Foster 3603W, 1/4" Industrial Coupler x 1/4" Hose ID, 3 Series, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3603W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — the...

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$ 308.00
$ 308.00 - $ 308.00
$ 308.00
$ 247.00
$ 247.00 - $ 247.00
$ 247.00
Save 20% Save %

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