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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 %
$ 428.00
$ 428.00 - $ 428.00
$ 428.00
$ 342.00
$ 342.00 - $ 342.00
$ 342.00

Foster SL2803, 1/4" Industrial Coupler x 1/8" Female NPT, 3 Series, Automatic Sleeve Lock, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SL2803 is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 428.00
$ 428.00 - $ 428.00
$ 428.00
$ 342.00
$ 342.00 - $ 342.00
$ 342.00
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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 %
$ 474.00
$ 474.00 - $ 474.00
$ 474.00
$ 380.00
$ 380.00 - $ 380.00
$ 380.00

Foster FM2803S, 1/4" Industrial Coupler x 1/8" Female NPT, 3 Series, Automatic, Steam/EPDM, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster FM2803S is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — t...

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$ 474.00
$ 474.00 - $ 474.00
$ 474.00
$ 380.00
$ 380.00 - $ 380.00
$ 380.00
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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 %
$ 415.00
$ 415.00 - $ 415.00
$ 415.00
$ 333.00
$ 333.00 - $ 333.00
$ 333.00

Foster FM2803, 1/4" Industrial Coupler x 1/8" Female NPT, 3 Series, Automatic, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster FM2803 is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 415.00
$ 415.00 - $ 415.00
$ 415.00
$ 333.00
$ 333.00 - $ 333.00
$ 333.00
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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 %
$ 243.00
$ 243.00 - $ 243.00
$ 243.00
$ 194.00
$ 194.00 - $ 194.00
$ 194.00

Foster SG3703, 1/4" Industrial Coupler x 3/8" Hose ID, 3 Series, Sleeve Guard, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SG3703 is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 243.00
$ 243.00 - $ 243.00
$ 243.00
$ 194.00
$ 194.00 - $ 194.00
$ 194.00
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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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$ 241.00
$ 241.00 - $ 241.00
$ 241.00
$ 193.00
$ 193.00 - $ 193.00
$ 193.00

Foster SG3603, 1/4" Industrial Coupler x 1/4" Hose ID, 3 Series, Sleeve Guard, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SG3603 is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 241.00
$ 241.00 - $ 241.00
$ 241.00
$ 193.00
$ 193.00 - $ 193.00
$ 193.00
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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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$ 269.00
$ 269.00 - $ 269.00
$ 269.00
$ 216.00
$ 216.00 - $ 216.00
$ 216.00

Foster SG1713, 1/4" Industrial Coupler x 3/8" Push-On Hose Stem, 3 Series, Sleeve Guard, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SG1713 is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 269.00
$ 269.00 - $ 269.00
$ 269.00
$ 216.00
$ 216.00 - $ 216.00
$ 216.00
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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 %
$ 266.00
$ 266.00 - $ 266.00
$ 266.00
$ 212.00
$ 212.00 - $ 212.00
$ 212.00

Foster SG1513, 1/4" Industrial Coupler x 1/4" Push-On Hose Stem, 3 Series, Sleeve Guard, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SG1513 is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 266.00
$ 266.00 - $ 266.00
$ 266.00
$ 212.00
$ 212.00 - $ 212.00
$ 212.00
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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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$ 251.00
$ 251.00 - $ 251.00
$ 251.00
$ 200.00
$ 200.00 - $ 200.00
$ 200.00

Foster SG3303, 1/4" Industrial Coupler x 3/8" Male NPT, 3 Series, Sleeve Guard, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SG3303 is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 251.00
$ 251.00 - $ 251.00
$ 251.00
$ 200.00
$ 200.00 - $ 200.00
$ 200.00
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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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$ 284.00
$ 284.00 - $ 284.00
$ 284.00
$ 227.00
$ 227.00 - $ 227.00
$ 227.00

Foster SG3103D, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Sleeve Guard, Dill Valve, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SG3103D is a Brass 1/4" industrial coupler from the Foster 3 Series — the ...

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$ 284.00
$ 284.00 - $ 284.00
$ 284.00
$ 227.00
$ 227.00 - $ 227.00
$ 227.00
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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 %
$ 232.00
$ 232.00 - $ 232.00
$ 232.00
$ 186.00
$ 186.00 - $ 186.00
$ 186.00

Foster SG3103, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Sleeve Guard, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SG3103 is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 232.00
$ 232.00 - $ 232.00
$ 232.00
$ 186.00
$ 186.00 - $ 186.00
$ 186.00
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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 %
$ 316.00
$ 316.00 - $ 316.00
$ 316.00
$ 251.00
$ 251.00 - $ 251.00
$ 251.00

Foster SG2903, 1/4" Industrial Coupler x 1/8" Male NPT, 3 Series, Sleeve Guard, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SG2903 is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 316.00
$ 316.00 - $ 316.00
$ 316.00
$ 251.00
$ 251.00 - $ 251.00
$ 251.00
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 %
$ 248.00
$ 248.00 - $ 248.00
$ 248.00
$ 198.00
$ 198.00 - $ 198.00
$ 198.00

Foster SG3203, 1/4" Industrial Coupler x 3/8" Female NPT, 3 Series, Sleeve Guard, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SG3203 is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 248.00
$ 248.00 - $ 248.00
$ 248.00
$ 198.00
$ 198.00 - $ 198.00
$ 198.00
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 %
$ 209.00
$ 209.00 - $ 209.00
$ 209.00
$ 168.00
$ 168.00 - $ 168.00
$ 168.00

Foster SG3003LV, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, Sleeve Guard, Less Valve, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SG3003LV is a Brass 1/4" industrial coupler from the Foster 3 Series — the...

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$ 209.00
$ 209.00 - $ 209.00
$ 209.00
$ 168.00
$ 168.00 - $ 168.00
$ 168.00
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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 %
$ 230.00
$ 230.00 - $ 230.00
$ 230.00
$ 184.00
$ 184.00 - $ 184.00
$ 184.00

Foster SG3003, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, Sleeve Guard, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SG3003 is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 230.00
$ 230.00 - $ 230.00
$ 230.00
$ 184.00
$ 184.00 - $ 184.00
$ 184.00
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 %
$ 383.00
$ 383.00 - $ 383.00
$ 383.00
$ 307.00
$ 307.00 - $ 307.00
$ 307.00

Foster SG2803, 1/4" Industrial Coupler x 1/8" Female NPT, 3 Series, Sleeve Guard, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SG2803 is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 383.00
$ 383.00 - $ 383.00
$ 383.00
$ 307.00
$ 307.00 - $ 307.00
$ 307.00
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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 %
$ 89.00
$ 89.00 - $ 89.00
$ 89.00
$ 72.00
$ 72.00 - $ 72.00
$ 72.00

Foster 3SDC, 1/4" 3 Series Socket Dust Cap, Steel

Protect your 1/4" 3 Series quick sockets when not in use. The Foster 3SDC dust cap keeps dirt, chips, and moisture out of the coupling, helping pre...

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$ 89.00
$ 89.00 - $ 89.00
$ 89.00
$ 72.00
$ 72.00 - $ 72.00
$ 72.00
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 %
$ 433.00
$ 433.00 - $ 433.00
$ 433.00
$ 348.00
$ 348.00 - $ 348.00
$ 348.00

Foster BLSD13-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 3/8" ID x 13/16" OD, 3 Series, Ball Lock, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BLSD13-3 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series...

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$ 433.00
$ 433.00 - $ 433.00
$ 433.00
$ 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 %
$ 401.00
$ 401.00 - $ 401.00
$ 401.00
$ 321.00
$ 321.00 - $ 321.00
$ 321.00

Foster SD13-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 3/8" ID x 13/16" OD, 3 Series, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SD13-3 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series —...

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$ 401.00
$ 401.00 - $ 401.00
$ 401.00
$ 321.00
$ 321.00 - $ 321.00
$ 321.00
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 %
$ 426.00
$ 426.00 - $ 426.00
$ 426.00
$ 341.00
$ 341.00 - $ 341.00
$ 341.00

Foster BLSD11-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 3/8" ID x 3/4" OD, 3 Series, Ball Lock, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BLSD11-3 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series...

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$ 426.00
$ 426.00 - $ 426.00
$ 426.00
$ 341.00
$ 341.00 - $ 341.00
$ 341.00
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 %
$ 394.00
$ 394.00 - $ 394.00
$ 394.00
$ 316.00
$ 316.00 - $ 316.00
$ 316.00

Foster SD11-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 3/8" ID x 3/4" OD, 3 Series, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SD11-3 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series —...

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$ 394.00
$ 394.00 - $ 394.00
$ 394.00
$ 316.00
$ 316.00 - $ 316.00
$ 316.00
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 %
$ 392.00
$ 392.00 - $ 392.00
$ 392.00
$ 314.00
$ 314.00 - $ 314.00
$ 314.00

Foster BLSD9-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 3/8" ID x 11/16" OD, 3 Series, Ball Lock, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BLSD9-3 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series ...

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$ 392.00
$ 392.00 - $ 392.00
$ 392.00
$ 314.00
$ 314.00 - $ 314.00
$ 314.00
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 %
$ 365.00
$ 365.00 - $ 365.00
$ 365.00
$ 292.00
$ 292.00 - $ 292.00
$ 292.00

Foster SD9-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 3/8" ID x 11/16" OD, 3 Series, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SD9-3 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series — ...

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$ 365.00
$ 365.00 - $ 365.00
$ 365.00
$ 292.00
$ 292.00 - $ 292.00
$ 292.00
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 %
$ 385.00
$ 385.00 - $ 385.00
$ 385.00
$ 308.00
$ 308.00 - $ 308.00
$ 308.00

Foster BLSD7-3, 1/4" Industrial Coupler x Reusable Hose Fitting, 3/8" ID x 5/8" OD, 3 Series, Ball Lock, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BLSD7-3 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
$ 308.00
$ 308.00 - $ 308.00
$ 308.00
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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 %
$ 362.00
$ 362.00 - $ 362.00
$ 362.00
$ 289.00
$ 289.00 - $ 289.00
$ 289.00

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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$ 362.00
$ 362.00 - $ 362.00
$ 362.00
$ 289.00
$ 289.00 - $ 289.00
$ 289.00
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