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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 %
$ 316.00
$ 316.00 - $ 316.00
$ 316.00
$ 253.00
$ 253.00 - $ 253.00
$ 253.00

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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$ 316.00
$ 316.00 - $ 316.00
$ 316.00
$ 253.00
$ 253.00 - $ 253.00
$ 253.00
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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 %
$ 1,202.00
$ 1,202.00 - $ 1,202.00
$ 1,202.00
$ 961.00
$ 961.00 - $ 961.00
$ 961.00

Foster 3603S/S, 1/4" Industrial Coupler x 1/4" Hose ID, 3 Series, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3603S/S is a 303 Stainless 1/4" industrial coupler from the Foster 3 Serie...

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$ 1,202.00
$ 1,202.00 - $ 1,202.00
$ 1,202.00
$ 961.00
$ 961.00 - $ 961.00
$ 961.00
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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 %
$ 325.00
$ 325.00 - $ 325.00
$ 325.00
$ 261.00
$ 261.00 - $ 261.00
$ 261.00

Foster 3603S, 1/4" Industrial Coupler x 1/4" Hose ID, 3 Series, Steam/EPDM, Brass/SS

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

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$ 325.00
$ 325.00 - $ 325.00
$ 325.00
$ 261.00
$ 261.00 - $ 261.00
$ 261.00
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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 %
$ 291.00
$ 291.00 - $ 291.00
$ 291.00
$ 232.00
$ 232.00 - $ 232.00
$ 232.00

Foster BL3603, 1/4" Industrial Coupler x 1/4" Hose ID, 3 Series, Ball Lock, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BL3603 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series —...

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$ 291.00
$ 291.00 - $ 291.00
$ 291.00
$ 232.00
$ 232.00 - $ 232.00
$ 232.00
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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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$ 257.00
$ 257.00 - $ 257.00
$ 257.00
$ 205.00
$ 205.00 - $ 205.00
$ 205.00

Foster 3603, 1/4" Industrial Coupler x 1/4" Hose ID, 3 Series, Brass/Steel

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

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$ 257.00
$ 257.00 - $ 257.00
$ 257.00
$ 205.00
$ 205.00 - $ 205.00
$ 205.00
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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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$ 360.00
$ 360.00 - $ 360.00
$ 360.00
$ 287.00
$ 287.00 - $ 287.00
$ 287.00

Foster 1713W, 1/4" Industrial Coupler x 3/8" Push-On Hose Stem, 3 Series, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 1713W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — the...

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$ 360.00
$ 360.00 - $ 360.00
$ 360.00
$ 287.00
$ 287.00 - $ 287.00
$ 287.00
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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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$ 332.00
$ 332.00 - $ 332.00
$ 332.00
$ 266.00
$ 266.00 - $ 266.00
$ 266.00

Foster BL1713, 1/4" Industrial Coupler x 3/8" Push-On Hose Stem, 3 Series, Ball Lock, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BL1713 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series —...

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$ 332.00
$ 332.00 - $ 332.00
$ 332.00
$ 266.00
$ 266.00 - $ 266.00
$ 266.00
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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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$ 289.00
$ 289.00 - $ 289.00
$ 289.00
$ 230.00
$ 230.00 - $ 230.00
$ 230.00

Foster 1713, 1/4" Industrial Coupler x 3/8" Push-On Hose Stem, 3 Series, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 1713 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series — t...

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$ 289.00
$ 289.00 - $ 289.00
$ 289.00
$ 230.00
$ 230.00 - $ 230.00
$ 230.00
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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
$ 291.00
$ 291.00 - $ 291.00
$ 291.00

Foster 1513W, 1/4" Industrial Coupler x 1/4" Push-On Hose Stem, 3 Series, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 1513W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — the...

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$ 362.00
$ 362.00 - $ 362.00
$ 362.00
$ 291.00
$ 291.00 - $ 291.00
$ 291.00
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 %
$ 325.00
$ 325.00 - $ 325.00
$ 325.00
$ 261.00
$ 261.00 - $ 261.00
$ 261.00

Foster BL1513, 1/4" Industrial Coupler x 1/4" Push-On Hose Stem, 3 Series, Ball Lock, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BL1513 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series —...

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$ 325.00
$ 325.00 - $ 325.00
$ 325.00
$ 261.00
$ 261.00 - $ 261.00
$ 261.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
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$ 286.00
$ 286.00 - $ 286.00
$ 286.00
$ 229.00
$ 229.00 - $ 229.00
$ 229.00

Foster 1513, 1/4" Industrial Coupler x 1/4" Push-On Hose Stem, 3 Series, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 1513 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series — t...

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$ 286.00
$ 286.00 - $ 286.00
$ 286.00
$ 229.00
$ 229.00 - $ 229.00
$ 229.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
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$ 334.00
$ 334.00 - $ 334.00
$ 334.00
$ 268.00
$ 268.00 - $ 268.00
$ 268.00

Foster 3303W, 1/4" Industrial Coupler x 3/8" Male NPT, 3 Series, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3303W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — the...

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$ 334.00
$ 334.00 - $ 334.00
$ 334.00
$ 268.00
$ 268.00 - $ 268.00
$ 268.00
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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 %
$ 1,263.00
$ 1,263.00 - $ 1,263.00
$ 1,263.00
$ 1,009.00
$ 1,009.00 - $ 1,009.00
$ 1,009.00

Foster BL3303S/S, 1/4" Industrial Coupler x 3/8" Male NPT, 3 Series, Ball Lock, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BL3303S/S is a 303 Stainless 1/4" industrial coupler from the Foster 3 Ser...

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$ 1,263.00
$ 1,263.00 - $ 1,263.00
$ 1,263.00
$ 1,009.00
$ 1,009.00 - $ 1,009.00
$ 1,009.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
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$ 1,175.00
$ 1,175.00 - $ 1,175.00
$ 1,175.00
$ 940.00
$ 940.00 - $ 940.00
$ 940.00

Foster 3303S/S, 1/4" Industrial Coupler x 3/8" Male NPT, 3 Series, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3303S/S is a 303 Stainless 1/4" industrial coupler from the Foster 3 Serie...

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$ 1,175.00
$ 1,175.00 - $ 1,175.00
$ 1,175.00
$ 940.00
$ 940.00 - $ 940.00
$ 940.00
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 %
$ 305.00
$ 305.00 - $ 305.00
$ 305.00
$ 245.00
$ 245.00 - $ 245.00
$ 245.00

Foster 3303H, 1/4" Industrial Coupler x 3/8" Male NPT, 3 Series, Heat/Viton, Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3303H is a Steel 1/4" industrial coupler from the Foster 3 Series — the mo...

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$ 305.00
$ 305.00 - $ 305.00
$ 305.00
$ 245.00
$ 245.00 - $ 245.00
$ 245.00
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 %
$ 303.00
$ 303.00 - $ 303.00
$ 303.00
$ 243.00
$ 243.00 - $ 243.00
$ 243.00

Foster BL3303, 1/4" Industrial Coupler x 3/8" Male NPT, 3 Series, Ball Lock, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BL3303 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series —...

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$ 303.00
$ 303.00 - $ 303.00
$ 303.00
$ 243.00
$ 243.00 - $ 243.00
$ 243.00
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 %
$ 268.00
$ 268.00 - $ 268.00
$ 268.00
$ 214.00
$ 214.00 - $ 214.00
$ 214.00

Foster 3303, 1/4" Industrial Coupler x 3/8" Male NPT, 3 Series, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3303 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series — t...

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$ 268.00
$ 268.00 - $ 268.00
$ 268.00
$ 214.00
$ 214.00 - $ 214.00
$ 214.00
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 %
$ 378.00
$ 378.00 - $ 378.00
$ 378.00
$ 302.00
$ 302.00 - $ 302.00
$ 302.00

Foster BL3103W, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Ball Lock, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BL3103W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — t...

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$ 378.00
$ 378.00 - $ 378.00
$ 378.00
$ 302.00
$ 302.00 - $ 302.00
$ 302.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
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$ 312.00
$ 312.00 - $ 312.00
$ 312.00
$ 250.00
$ 250.00 - $ 250.00
$ 250.00

Foster 3103W, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3103W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — the...

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$ 312.00
$ 312.00 - $ 312.00
$ 312.00
$ 250.00
$ 250.00 - $ 250.00
$ 250.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
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$ 808.00
$ 808.00 - $ 808.00
$ 808.00
$ 648.00
$ 648.00 - $ 648.00
$ 648.00

Foster 3103S/SLV, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Less Valve, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3103S/SLV is a 303 Stainless 1/4" industrial coupler from the Foster 3 Ser...

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$ 808.00
$ 808.00 - $ 808.00
$ 808.00
$ 648.00
$ 648.00 - $ 648.00
$ 648.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
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$ 849.00
$ 849.00 - $ 849.00
$ 849.00
$ 680.00
$ 680.00 - $ 680.00
$ 680.00

Foster 3103S/SH, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Heat/Viton, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3103S/SH is a 303 Stainless 1/4" industrial coupler from the Foster 3 Seri...

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$ 849.00
$ 849.00 - $ 849.00
$ 849.00
$ 680.00
$ 680.00 - $ 680.00
$ 680.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
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$ 860.00
$ 860.00 - $ 860.00
$ 860.00
$ 687.00
$ 687.00 - $ 687.00
$ 687.00

Foster BL3103S/S, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Ball Lock, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BL3103S/S is a 303 Stainless 1/4" industrial coupler from the Foster 3 Ser...

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$ 860.00
$ 860.00 - $ 860.00
$ 860.00
$ 687.00
$ 687.00 - $ 687.00
$ 687.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
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$ 803.00
$ 803.00 - $ 803.00
$ 803.00
$ 642.00
$ 642.00 - $ 642.00
$ 642.00

Foster 3103S/S, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3103S/S is a 303 Stainless 1/4" industrial coupler from the Foster 3 Serie...

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$ 803.00
$ 803.00 - $ 803.00
$ 803.00
$ 642.00
$ 642.00 - $ 642.00
$ 642.00
Save 20% Save %
Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass
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$ 309.00
$ 309.00 - $ 309.00
$ 309.00
$ 248.00
$ 248.00 - $ 248.00
$ 248.00

Foster 3103S, 1/4" Industrial Coupler x 1/4" Male NPT, 3 Series, Steam/EPDM, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3103S is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — the...

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$ 309.00
$ 309.00 - $ 309.00
$ 309.00
$ 248.00
$ 248.00 - $ 248.00
$ 248.00
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