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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 %
$ 384.00
$ 384.00 - $ 384.00
$ 384.00
$ 306.00
$ 306.00 - $ 306.00
$ 306.00

Foster SD7-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 3/8" ID x 5/8" OD, 3 Series, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SD7-3 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series — ...

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$ 384.00
$ 384.00 - $ 384.00
$ 384.00
$ 306.00
$ 306.00 - $ 306.00
$ 306.00
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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 %
$ 622.00
$ 622.00 - $ 622.00
$ 622.00
$ 497.00
$ 497.00 - $ 497.00
$ 497.00

Foster BLSC7-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 5/16" ID x 5/8" OD, 3 Series, Ball Lock, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BLSC7-3 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series ...

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$ 622.00
$ 622.00 - $ 622.00
$ 622.00
$ 497.00
$ 497.00 - $ 497.00
$ 497.00
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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 %
$ 624.00
$ 624.00 - $ 624.00
$ 624.00
$ 499.00
$ 499.00 - $ 499.00
$ 499.00

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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$ 624.00
$ 624.00 - $ 624.00
$ 624.00
$ 499.00
$ 499.00 - $ 499.00
$ 499.00
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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 %
$ 614.00
$ 614.00 - $ 614.00
$ 614.00
$ 492.00
$ 492.00 - $ 492.00
$ 492.00

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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$ 614.00
$ 614.00 - $ 614.00
$ 614.00
$ 492.00
$ 492.00 - $ 492.00
$ 492.00
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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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$ 616.00
$ 616.00 - $ 616.00
$ 616.00
$ 493.00
$ 493.00 - $ 493.00
$ 493.00

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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$ 616.00
$ 616.00 - $ 616.00
$ 616.00
$ 493.00
$ 493.00 - $ 493.00
$ 493.00
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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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$ 505.00
$ 505.00 - $ 505.00
$ 505.00
$ 405.00
$ 405.00 - $ 405.00
$ 405.00

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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$ 505.00
$ 505.00 - $ 505.00
$ 505.00
$ 405.00
$ 405.00 - $ 405.00
$ 405.00
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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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$ 435.00
$ 435.00 - $ 435.00
$ 435.00
$ 348.00
$ 348.00 - $ 348.00
$ 348.00

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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$ 435.00
$ 435.00 - $ 435.00
$ 435.00
$ 348.00
$ 348.00 - $ 348.00
$ 348.00
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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 %
$ 1,274.00
$ 1,274.00 - $ 1,274.00
$ 1,274.00
$ 1,019.00
$ 1,019.00 - $ 1,019.00
$ 1,019.00

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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$ 1,274.00
$ 1,274.00 - $ 1,274.00
$ 1,274.00
$ 1,019.00
$ 1,019.00 - $ 1,019.00
$ 1,019.00
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 %
$ 1,200.00
$ 1,200.00 - $ 1,200.00
$ 1,200.00
$ 960.00
$ 960.00 - $ 960.00
$ 960.00

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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$ 1,200.00
$ 1,200.00 - $ 1,200.00
$ 1,200.00
$ 960.00
$ 960.00 - $ 960.00
$ 960.00
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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 %
$ 399.00
$ 399.00 - $ 399.00
$ 399.00
$ 320.00
$ 320.00 - $ 320.00
$ 320.00

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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$ 399.00
$ 399.00 - $ 399.00
$ 399.00
$ 320.00
$ 320.00 - $ 320.00
$ 320.00
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 %
$ 369.00
$ 369.00 - $ 369.00
$ 369.00
$ 295.00
$ 295.00 - $ 295.00
$ 295.00

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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$ 369.00
$ 369.00 - $ 369.00
$ 369.00
$ 295.00
$ 295.00 - $ 295.00
$ 295.00
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 %
$ 537.00
$ 537.00 - $ 537.00
$ 537.00
$ 429.00
$ 429.00 - $ 429.00
$ 429.00

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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$ 537.00
$ 537.00 - $ 537.00
$ 537.00
$ 429.00
$ 429.00 - $ 429.00
$ 429.00
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 %
$ 418.00
$ 418.00 - $ 418.00
$ 418.00
$ 333.00
$ 333.00 - $ 333.00
$ 333.00

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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$ 418.00
$ 418.00 - $ 418.00
$ 418.00
$ 333.00
$ 333.00 - $ 333.00
$ 333.00
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 %
$ 399.00
$ 399.00 - $ 399.00
$ 399.00
$ 320.00
$ 320.00 - $ 320.00
$ 320.00

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 — ...

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$ 399.00
$ 399.00 - $ 399.00
$ 399.00
$ 320.00
$ 320.00 - $ 320.00
$ 320.00
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 %
$ 448.00
$ 448.00 - $ 448.00
$ 448.00
$ 359.00
$ 359.00 - $ 359.00
$ 359.00

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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$ 448.00
$ 448.00 - $ 448.00
$ 448.00
$ 359.00
$ 359.00 - $ 359.00
$ 359.00
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 %
$ 2,075.00
$ 2,075.00 - $ 2,075.00
$ 2,075.00
$ 1,661.00
$ 1,661.00 - $ 1,661.00
$ 1,661.00

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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$ 2,075.00
$ 2,075.00 - $ 2,075.00
$ 2,075.00
$ 1,661.00
$ 1,661.00 - $ 1,661.00
$ 1,661.00
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 %
$ 497.00
$ 497.00 - $ 497.00
$ 497.00
$ 397.00
$ 397.00 - $ 397.00
$ 397.00

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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$ 497.00
$ 497.00 - $ 497.00
$ 497.00
$ 397.00
$ 397.00 - $ 397.00
$ 397.00
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 %
$ 374.00
$ 374.00 - $ 374.00
$ 374.00
$ 299.00
$ 299.00 - $ 299.00
$ 299.00

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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$ 374.00
$ 374.00 - $ 374.00
$ 374.00
$ 299.00
$ 299.00 - $ 299.00
$ 299.00
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 %
$ 1,366.00
$ 1,366.00 - $ 1,366.00
$ 1,366.00
$ 1,092.00
$ 1,092.00 - $ 1,092.00
$ 1,092.00

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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$ 1,366.00
$ 1,366.00 - $ 1,366.00
$ 1,366.00
$ 1,092.00
$ 1,092.00 - $ 1,092.00
$ 1,092.00
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 %
$ 1,300.00
$ 1,300.00 - $ 1,300.00
$ 1,300.00
$ 1,041.00
$ 1,041.00 - $ 1,041.00
$ 1,041.00

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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$ 1,300.00
$ 1,300.00 - $ 1,300.00
$ 1,300.00
$ 1,041.00
$ 1,041.00 - $ 1,041.00
$ 1,041.00
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 %
$ 371.00
$ 371.00 - $ 371.00
$ 371.00
$ 297.00
$ 297.00 - $ 297.00
$ 297.00

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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$ 371.00
$ 371.00 - $ 371.00
$ 371.00
$ 297.00
$ 297.00 - $ 297.00
$ 297.00
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 %
$ 335.00
$ 335.00 - $ 335.00
$ 335.00
$ 269.00
$ 269.00 - $ 269.00
$ 269.00

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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$ 335.00
$ 335.00 - $ 335.00
$ 335.00
$ 269.00
$ 269.00 - $ 269.00
$ 269.00
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 %
$ 297.00
$ 297.00 - $ 297.00
$ 297.00
$ 238.00
$ 238.00 - $ 238.00
$ 238.00

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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$ 297.00
$ 297.00 - $ 297.00
$ 297.00
$ 238.00
$ 238.00 - $ 238.00
$ 238.00
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 %
$ 331.00
$ 331.00 - $ 331.00
$ 331.00
$ 265.00
$ 265.00 - $ 265.00
$ 265.00

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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$ 331.00
$ 331.00 - $ 331.00
$ 331.00
$ 265.00
$ 265.00 - $ 265.00
$ 265.00
Save 20% Save %

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