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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 %
$ 527.00
$ 527.00 - $ 527.00
$ 527.00
$ 421.00
$ 421.00 - $ 421.00
$ 421.00

Foster SL3103W, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Automatic Sleeve Lock, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SL3103W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — t...

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$ 527.00
$ 527.00 - $ 527.00
$ 527.00
$ 421.00
$ 421.00 - $ 421.00
$ 421.00
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 %
$ 444.00
$ 444.00 - $ 444.00
$ 444.00
$ 355.00
$ 355.00 - $ 355.00
$ 355.00

Foster FM3103W, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Automatic, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster FM3103W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — t...

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$ 444.00
$ 444.00 - $ 444.00
$ 444.00
$ 355.00
$ 355.00 - $ 355.00
$ 355.00
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 %
$ 437.00
$ 437.00 - $ 437.00
$ 437.00
$ 350.00
$ 350.00 - $ 350.00
$ 350.00

Foster FM3103S, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Automatic, Steam/EPDM, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster FM3103S is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — t...

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$ 437.00
$ 437.00 - $ 437.00
$ 437.00
$ 350.00
$ 350.00 - $ 350.00
$ 350.00
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 %
$ 507.00
$ 507.00 - $ 507.00
$ 507.00
$ 406.00
$ 406.00 - $ 406.00
$ 406.00

Foster SL3103HW, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Automatic Sleeve Lock, Hot Water/Viton, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SL3103HW is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — ...

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$ 507.00
$ 507.00 - $ 507.00
$ 507.00
$ 406.00
$ 406.00 - $ 406.00
$ 406.00
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 %
$ 444.00
$ 444.00 - $ 444.00
$ 444.00
$ 355.00
$ 355.00 - $ 355.00
$ 355.00

Foster FM3103HW, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Automatic, Hot Water/Viton, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster FM3103HW is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — ...

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$ 444.00
$ 444.00 - $ 444.00
$ 444.00
$ 355.00
$ 355.00 - $ 355.00
$ 355.00
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 %
$ 393.00
$ 393.00 - $ 393.00
$ 393.00
$ 315.00
$ 315.00 - $ 315.00
$ 315.00

Foster FM3103H, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Automatic, Heat/Viton, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster FM3103H is a Brass 1/4" industrial coupler from the Foster 3 Series — the ...

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$ 393.00
$ 393.00 - $ 393.00
$ 393.00
$ 315.00
$ 315.00 - $ 315.00
$ 315.00
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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 %
$ 479.00
$ 479.00 - $ 479.00
$ 479.00
$ 383.00
$ 383.00 - $ 383.00
$ 383.00

Foster SL3103D, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Automatic Sleeve Lock, Dill Valve, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SL3103D is a Brass 1/4" industrial coupler from the Foster 3 Series — the ...

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$ 479.00
$ 479.00 - $ 479.00
$ 479.00
$ 383.00
$ 383.00 - $ 383.00
$ 383.00
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 %
$ 390.00
$ 390.00 - $ 390.00
$ 390.00
$ 312.00
$ 312.00 - $ 312.00
$ 312.00

Foster FM3103D, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Automatic, Dill Valve, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster FM3103D is a Brass 1/4" industrial coupler from the Foster 3 Series — the ...

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$ 390.00
$ 390.00 - $ 390.00
$ 390.00
$ 312.00
$ 312.00 - $ 312.00
$ 312.00
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 %
$ 440.00
$ 440.00 - $ 440.00
$ 440.00
$ 352.00
$ 352.00 - $ 352.00
$ 352.00

Foster SL3103, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Automatic Sleeve Lock, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SL3103 is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 440.00
$ 440.00 - $ 440.00
$ 440.00
$ 352.00
$ 352.00 - $ 352.00
$ 352.00
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
$ 306.00
$ 306.00 - $ 306.00
$ 306.00

Foster FM3103, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Automatic, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster FM3103 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
$ 306.00
$ 306.00 - $ 306.00
$ 306.00
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 %
$ 461.00
$ 461.00 - $ 461.00
$ 461.00
$ 369.00
$ 369.00 - $ 369.00
$ 369.00

Foster SL2903, 1/4" Industrial Coupler x 1/8" Male NPT, 3 Series, Automatic Sleeve Lock, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SL2903 is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 461.00
$ 461.00 - $ 461.00
$ 461.00
$ 369.00
$ 369.00 - $ 369.00
$ 369.00
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 %
$ 376.00
$ 376.00 - $ 376.00
$ 376.00
$ 301.00
$ 301.00 - $ 301.00
$ 301.00

Foster FM2903, 1/4" Industrial Coupler x 1/8" Male NPT, 3 Series, Automatic, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster FM2903 is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 376.00
$ 376.00 - $ 376.00
$ 376.00
$ 301.00
$ 301.00 - $ 301.00
$ 301.00
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 %
$ 465.00
$ 465.00 - $ 465.00
$ 465.00
$ 373.00
$ 373.00 - $ 373.00
$ 373.00

Foster FM3203W, 1/4" Industrial Coupler x 3/8" Female NPT, 3 Series, Automatic, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster FM3203W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — t...

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$ 465.00
$ 465.00 - $ 465.00
$ 465.00
$ 373.00
$ 373.00 - $ 373.00
$ 373.00
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 FM3203H, 1/4" Industrial Coupler x 3/8" Female NPT, 3 Series, Automatic, Heat/Viton, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster FM3203H is a Brass 1/4" industrial coupler from the Foster 3 Series — the ...

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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 %
$ 409.00
$ 409.00 - $ 409.00
$ 409.00
$ 327.00
$ 327.00 - $ 327.00
$ 327.00

Foster SL3203, 1/4" Industrial Coupler x 3/8" Female NPT, 3 Series, Automatic Sleeve Lock, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SL3203 is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 409.00
$ 409.00 - $ 409.00
$ 409.00
$ 327.00
$ 327.00 - $ 327.00
$ 327.00
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 %
$ 386.00
$ 386.00 - $ 386.00
$ 386.00
$ 310.00
$ 310.00 - $ 310.00
$ 310.00

Foster FM3203, 1/4" Industrial Coupler x 3/8" Female NPT, 3 Series, Automatic, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster FM3203 is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

View full details
$ 386.00
$ 386.00 - $ 386.00
$ 386.00
$ 310.00
$ 310.00 - $ 310.00
$ 310.00
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 %
$ 500.00
$ 500.00 - $ 500.00
$ 500.00
$ 400.00
$ 400.00 - $ 400.00
$ 400.00

Foster SL3003W, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, Automatic Sleeve Lock, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SL3003W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — t...

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$ 500.00
$ 500.00 - $ 500.00
$ 500.00
$ 400.00
$ 400.00 - $ 400.00
$ 400.00
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 %
$ 437.00
$ 437.00 - $ 437.00
$ 437.00
$ 350.00
$ 350.00 - $ 350.00
$ 350.00

Foster FM3003W, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, Automatic, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster FM3003W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — t...

View full details
$ 437.00
$ 437.00 - $ 437.00
$ 437.00
$ 350.00
$ 350.00 - $ 350.00
$ 350.00
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 %
$ 433.00
$ 433.00 - $ 433.00
$ 433.00
$ 346.00
$ 346.00 - $ 346.00
$ 346.00

Foster FM3003S, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, Automatic, Steam/EPDM, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster FM3003S is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — t...

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$ 433.00
$ 433.00 - $ 433.00
$ 433.00
$ 346.00
$ 346.00 - $ 346.00
$ 346.00
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 %
$ 437.00
$ 437.00 - $ 437.00
$ 437.00
$ 350.00
$ 350.00 - $ 350.00
$ 350.00

Foster FM3003HW, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, Automatic, Hot Water/Viton, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster FM3003HW is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — ...

View full details
$ 437.00
$ 437.00 - $ 437.00
$ 437.00
$ 350.00
$ 350.00 - $ 350.00
$ 350.00
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 %
$ 395.00
$ 395.00 - $ 395.00
$ 395.00
$ 317.00
$ 317.00 - $ 317.00
$ 317.00

Foster SL3003, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, Automatic Sleeve Lock, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster SL3003 is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 395.00
$ 395.00 - $ 395.00
$ 395.00
$ 317.00
$ 317.00 - $ 317.00
$ 317.00
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 %
$ 373.00
$ 373.00 - $ 373.00
$ 373.00
$ 298.00
$ 298.00 - $ 298.00
$ 298.00

Foster FM3003, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, Automatic, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster FM3003 is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 373.00
$ 373.00 - $ 373.00
$ 373.00
$ 298.00
$ 298.00 - $ 298.00
$ 298.00
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 %
$ 428.00
$ 428.00 - $ 428.00
$ 428.00
$ 343.00
$ 343.00 - $ 343.00
$ 343.00

Foster FM2803W, 1/4" Industrial Coupler x 1/8" Female NPT, 3 Series, Automatic, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster FM2803W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — t...

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$ 428.00
$ 428.00 - $ 428.00
$ 428.00
$ 343.00
$ 343.00 - $ 343.00
$ 343.00
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
$ 334.00
$ 334.00 - $ 334.00
$ 334.00

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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$ 418.00
$ 418.00 - $ 418.00
$ 418.00
$ 334.00
$ 334.00 - $ 334.00
$ 334.00
Save 20% Save %

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