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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 %
$ 404.00
$ 404.00 - $ 404.00
$ 404.00
$ 323.00
$ 323.00 - $ 323.00
$ 323.00

Foster FM3303, 1/4" Industrial Coupler x 3/8" Male NPT, 3 Series, Automatic, Brass

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster FM3303 is a Brass 1/4" industrial coupler from the Foster 3 Series — the m...

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$ 404.00
$ 404.00 - $ 404.00
$ 404.00
$ 323.00
$ 323.00 - $ 323.00
$ 323.00
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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 %
$ 546.00
$ 546.00 - $ 546.00
$ 546.00
$ 436.00
$ 436.00 - $ 436.00
$ 436.00

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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$ 546.00
$ 546.00 - $ 546.00
$ 546.00
$ 436.00
$ 436.00 - $ 436.00
$ 436.00
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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 %
$ 459.00
$ 459.00 - $ 459.00
$ 459.00
$ 368.00
$ 368.00 - $ 368.00
$ 368.00

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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$ 459.00
$ 459.00 - $ 459.00
$ 459.00
$ 368.00
$ 368.00 - $ 368.00
$ 368.00
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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 %
$ 452.00
$ 452.00 - $ 452.00
$ 452.00
$ 362.00
$ 362.00 - $ 362.00
$ 362.00

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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$ 452.00
$ 452.00 - $ 452.00
$ 452.00
$ 362.00
$ 362.00 - $ 362.00
$ 362.00
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 %
$ 524.00
$ 524.00 - $ 524.00
$ 524.00
$ 420.00
$ 420.00 - $ 420.00
$ 420.00

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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$ 524.00
$ 524.00 - $ 524.00
$ 524.00
$ 420.00
$ 420.00 - $ 420.00
$ 420.00
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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 %
$ 459.00
$ 459.00 - $ 459.00
$ 459.00
$ 368.00
$ 368.00 - $ 368.00
$ 368.00

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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$ 459.00
$ 459.00 - $ 459.00
$ 459.00
$ 368.00
$ 368.00 - $ 368.00
$ 368.00
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 %
$ 407.00
$ 407.00 - $ 407.00
$ 407.00
$ 326.00
$ 326.00 - $ 326.00
$ 326.00

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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$ 407.00
$ 407.00 - $ 407.00
$ 407.00
$ 326.00
$ 326.00 - $ 326.00
$ 326.00
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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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$ 495.00
$ 495.00 - $ 495.00
$ 495.00
$ 396.00
$ 396.00 - $ 396.00
$ 396.00

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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$ 495.00
$ 495.00 - $ 495.00
$ 495.00
$ 396.00
$ 396.00 - $ 396.00
$ 396.00
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 %
$ 404.00
$ 404.00 - $ 404.00
$ 404.00
$ 323.00
$ 323.00 - $ 323.00
$ 323.00

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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$ 404.00
$ 404.00 - $ 404.00
$ 404.00
$ 323.00
$ 323.00 - $ 323.00
$ 323.00
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 %
$ 456.00
$ 456.00 - $ 456.00
$ 456.00
$ 364.00
$ 364.00 - $ 364.00
$ 364.00

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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$ 456.00
$ 456.00 - $ 456.00
$ 456.00
$ 364.00
$ 364.00 - $ 364.00
$ 364.00
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 %
$ 396.00
$ 396.00 - $ 396.00
$ 396.00
$ 317.00
$ 317.00 - $ 317.00
$ 317.00

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...

View full details
$ 396.00
$ 396.00 - $ 396.00
$ 396.00
$ 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 %
$ 477.00
$ 477.00 - $ 477.00
$ 477.00
$ 382.00
$ 382.00 - $ 382.00
$ 382.00

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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$ 477.00
$ 477.00 - $ 477.00
$ 477.00
$ 382.00
$ 382.00 - $ 382.00
$ 382.00
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 %
$ 389.00
$ 389.00 - $ 389.00
$ 389.00
$ 312.00
$ 312.00 - $ 312.00
$ 312.00

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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$ 389.00
$ 389.00 - $ 389.00
$ 389.00
$ 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 %
$ 481.00
$ 481.00 - $ 481.00
$ 481.00
$ 386.00
$ 386.00 - $ 386.00
$ 386.00

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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$ 481.00
$ 481.00 - $ 481.00
$ 481.00
$ 386.00
$ 386.00 - $ 386.00
$ 386.00
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 %
$ 427.00
$ 427.00 - $ 427.00
$ 427.00
$ 342.00
$ 342.00 - $ 342.00
$ 342.00

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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$ 427.00
$ 427.00 - $ 427.00
$ 427.00
$ 342.00
$ 342.00 - $ 342.00
$ 342.00
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 %
$ 423.00
$ 423.00 - $ 423.00
$ 423.00
$ 339.00
$ 339.00 - $ 339.00
$ 339.00

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...

View full details
$ 423.00
$ 423.00 - $ 423.00
$ 423.00
$ 339.00
$ 339.00 - $ 339.00
$ 339.00
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 %
$ 400.00
$ 400.00 - $ 400.00
$ 400.00
$ 321.00
$ 321.00 - $ 321.00
$ 321.00

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...

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$ 400.00
$ 400.00 - $ 400.00
$ 400.00
$ 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 %
$ 517.00
$ 517.00 - $ 517.00
$ 517.00
$ 414.00
$ 414.00 - $ 414.00
$ 414.00

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...

View full details
$ 517.00
$ 517.00 - $ 517.00
$ 517.00
$ 414.00
$ 414.00 - $ 414.00
$ 414.00
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 %
$ 452.00
$ 452.00 - $ 452.00
$ 452.00
$ 362.00
$ 362.00 - $ 362.00
$ 362.00

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
$ 452.00
$ 452.00 - $ 452.00
$ 452.00
$ 362.00
$ 362.00 - $ 362.00
$ 362.00
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 %
$ 449.00
$ 449.00 - $ 449.00
$ 449.00
$ 359.00
$ 359.00 - $ 359.00
$ 359.00

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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$ 449.00
$ 449.00 - $ 449.00
$ 449.00
$ 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 %
$ 452.00
$ 452.00 - $ 452.00
$ 452.00
$ 362.00
$ 362.00 - $ 362.00
$ 362.00

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
$ 452.00
$ 452.00 - $ 452.00
$ 452.00
$ 362.00
$ 362.00 - $ 362.00
$ 362.00
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
$ 328.00
$ 328.00 - $ 328.00
$ 328.00

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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$ 409.00
$ 409.00 - $ 409.00
$ 409.00
$ 328.00
$ 328.00 - $ 328.00
$ 328.00
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
$ 308.00
$ 308.00 - $ 308.00
$ 308.00

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...

View full details
$ 386.00
$ 386.00 - $ 386.00
$ 386.00
$ 308.00
$ 308.00 - $ 308.00
$ 308.00
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 %
$ 443.00
$ 443.00 - $ 443.00
$ 443.00
$ 355.00
$ 355.00 - $ 355.00
$ 355.00

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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$ 443.00
$ 443.00 - $ 443.00
$ 443.00
$ 355.00
$ 355.00 - $ 355.00
$ 355.00
Save 20% Save %

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