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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.

  • Original price $ 21.39
    Original price $ 21.39 - Original price $ 21.39
    Original price $ 21.39
    Current price $ 17.09
    $ 17.09 - $ 17.09
    Current price $ 17.09

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

    In stock

    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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    Original price $ 21.39
    Original price $ 21.39 - Original price $ 21.39
    Original price $ 21.39
    Current price $ 17.09
    $ 17.09 - $ 17.09
    Current price $ 17.09
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  • Original price $ 24.59
    Original price $ 24.59 - Original price $ 24.59
    Original price $ 24.59
    Current price $ 19.69
    $ 19.69 - $ 19.69
    Current price $ 19.69

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

    In stock

    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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    Original price $ 24.59
    Original price $ 24.59 - Original price $ 24.59
    Original price $ 24.59
    Current price $ 19.69
    $ 19.69 - $ 19.69
    Current price $ 19.69
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  • Original price $ 23.99
    Original price $ 23.99 - Original price $ 23.99
    Original price $ 23.99
    Current price $ 19.19
    $ 19.19 - $ 19.19
    Current price $ 19.19

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

    In stock

    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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    Original price $ 23.99
    Original price $ 23.99 - Original price $ 23.99
    Original price $ 23.99
    Current price $ 19.19
    $ 19.19 - $ 19.19
    Current price $ 19.19
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  • Original price $ 26.59
    Original price $ 26.59 - Original price $ 26.59
    Original price $ 26.59
    Current price $ 21.29
    $ 21.29 - $ 21.29
    Current price $ 21.29

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

    In stock

    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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    Original price $ 26.59
    Original price $ 26.59 - Original price $ 26.59
    Original price $ 26.59
    Current price $ 21.29
    $ 21.29 - $ 21.29
    Current price $ 21.29
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  • Original price $ 23.29
    Original price $ 23.29 - Original price $ 23.29
    Original price $ 23.29
    Current price $ 18.69
    $ 18.69 - $ 18.69
    Current price $ 18.69

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

    In stock

    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...

    View full details
    Original price $ 23.29
    Original price $ 23.29 - Original price $ 23.29
    Original price $ 23.29
    Current price $ 18.69
    $ 18.69 - $ 18.69
    Current price $ 18.69
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  • Original price $ 13.59
    Original price $ 13.59 - Original price $ 13.59
    Original price $ 13.59
    Current price $ 10.89
    $ 10.89 - $ 10.89
    Current price $ 10.89

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

    In stock

    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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    Original price $ 13.59
    Original price $ 13.59 - Original price $ 13.59
    Original price $ 13.59
    Current price $ 10.89
    $ 10.89 - $ 10.89
    Current price $ 10.89
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  • Original price $ 13.49
    Original price $ 13.49 - Original price $ 13.49
    Original price $ 13.49
    Current price $ 10.79
    $ 10.79 - $ 10.79
    Current price $ 10.79

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

    In stock

    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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    Original price $ 13.49
    Original price $ 13.49 - Original price $ 13.49
    Original price $ 13.49
    Current price $ 10.79
    $ 10.79 - $ 10.79
    Current price $ 10.79
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  • Original price $ 15.09
    Original price $ 15.09 - Original price $ 15.09
    Original price $ 15.09
    Current price $ 12.09
    $ 12.09 - $ 12.09
    Current price $ 12.09

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

    In stock

    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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    Original price $ 15.09
    Original price $ 15.09 - Original price $ 15.09
    Original price $ 15.09
    Current price $ 12.09
    $ 12.09 - $ 12.09
    Current price $ 12.09
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  • Original price $ 14.89
    Original price $ 14.89 - Original price $ 14.89
    Original price $ 14.89
    Current price $ 11.89
    $ 11.89 - $ 11.89
    Current price $ 11.89

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

    In stock

    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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    Original price $ 14.89
    Original price $ 14.89 - Original price $ 14.89
    Original price $ 14.89
    Current price $ 11.89
    $ 11.89 - $ 11.89
    Current price $ 11.89
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  • Original price $ 14.09
    Original price $ 14.09 - Original price $ 14.09
    Original price $ 14.09
    Current price $ 11.19
    $ 11.19 - $ 11.19
    Current price $ 11.19

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

    In stock

    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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    Original price $ 14.09
    Original price $ 14.09 - Original price $ 14.09
    Original price $ 14.09
    Current price $ 11.19
    $ 11.19 - $ 11.19
    Current price $ 11.19
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  • Original price $ 15.89
    Original price $ 15.89 - Original price $ 15.89
    Original price $ 15.89
    Current price $ 12.69
    $ 12.69 - $ 12.69
    Current price $ 12.69

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

    In stock

    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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    Original price $ 15.89
    Original price $ 15.89 - Original price $ 15.89
    Original price $ 15.89
    Current price $ 12.69
    $ 12.69 - $ 12.69
    Current price $ 12.69
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  • Original price $ 12.99
    Original price $ 12.99 - Original price $ 12.99
    Original price $ 12.99
    Current price $ 10.39
    $ 10.39 - $ 10.39
    Current price $ 10.39

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

    In stock

    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...

    View full details
    Original price $ 12.99
    Original price $ 12.99 - Original price $ 12.99
    Original price $ 12.99
    Current price $ 10.39
    $ 10.39 - $ 10.39
    Current price $ 10.39
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  • Original price $ 17.69
    Original price $ 17.69 - Original price $ 17.69
    Original price $ 17.69
    Current price $ 14.09
    $ 14.09 - $ 14.09
    Current price $ 14.09

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

    In stock

    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...

    View full details
    Original price $ 17.69
    Original price $ 17.69 - Original price $ 17.69
    Original price $ 17.69
    Current price $ 14.09
    $ 14.09 - $ 14.09
    Current price $ 14.09
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  • Original price $ 13.89
    Original price $ 13.89 - Original price $ 13.89
    Original price $ 13.89
    Current price $ 11.09
    $ 11.09 - $ 11.09
    Current price $ 11.09

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

    In stock

    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...

    View full details
    Original price $ 13.89
    Original price $ 13.89 - Original price $ 13.89
    Original price $ 13.89
    Current price $ 11.09
    $ 11.09 - $ 11.09
    Current price $ 11.09
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  • Original price $ 11.69
    Original price $ 11.69 - Original price $ 11.69
    Original price $ 11.69
    Current price $ 9.39
    $ 9.39 - $ 9.39
    Current price $ 9.39

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

    In stock

    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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    Original price $ 11.69
    Original price $ 11.69 - Original price $ 11.69
    Original price $ 11.69
    Current price $ 9.39
    $ 9.39 - $ 9.39
    Current price $ 9.39
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  • Original price $ 12.89
    Original price $ 12.89 - Original price $ 12.89
    Original price $ 12.89
    Current price $ 10.29
    $ 10.29 - $ 10.29
    Current price $ 10.29

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

    In stock

    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...

    View full details
    Original price $ 12.89
    Original price $ 12.89 - Original price $ 12.89
    Original price $ 12.89
    Current price $ 10.29
    $ 10.29 - $ 10.29
    Current price $ 10.29
    Save 20% Save %
  • Original price $ 21.49
    Original price $ 21.49 - Original price $ 21.49
    Original price $ 21.49
    Current price $ 17.19
    $ 17.19 - $ 17.19
    Current price $ 17.19

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

    In stock

    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...

    View full details
    Original price $ 21.49
    Original price $ 21.49 - Original price $ 21.49
    Original price $ 21.49
    Current price $ 17.19
    $ 17.19 - $ 17.19
    Current price $ 17.19
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  • Original price $ 4.99
    Original price $ 4.99 - Original price $ 4.99
    Original price $ 4.99
    Current price $ 3.99
    $ 3.99 - $ 3.99
    Current price $ 3.99

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

    In stock

    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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    Original price $ 4.99
    Original price $ 4.99 - Original price $ 4.99
    Original price $ 4.99
    Current price $ 3.99
    $ 3.99 - $ 3.99
    Current price $ 3.99
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  • Original price $ 24.29
    Original price $ 24.29 - Original price $ 24.29
    Original price $ 24.29
    Current price $ 19.49
    $ 19.49 - $ 19.49
    Current price $ 19.49

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

    In stock

    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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    Original price $ 24.29
    Original price $ 24.29 - Original price $ 24.29
    Original price $ 24.29
    Current price $ 19.49
    $ 19.49 - $ 19.49
    Current price $ 19.49
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  • Original price $ 22.49
    Original price $ 22.49 - Original price $ 22.49
    Original price $ 22.49
    Current price $ 17.99
    $ 17.99 - $ 17.99
    Current price $ 17.99

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

    In stock

    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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    Original price $ 22.49
    Original price $ 22.49 - Original price $ 22.49
    Original price $ 22.49
    Current price $ 17.99
    $ 17.99 - $ 17.99
    Current price $ 17.99
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  • Original price $ 23.89
    Original price $ 23.89 - Original price $ 23.89
    Original price $ 23.89
    Current price $ 19.09
    $ 19.09 - $ 19.09
    Current price $ 19.09

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

    In stock

    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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    Original price $ 23.89
    Original price $ 23.89 - Original price $ 23.89
    Original price $ 23.89
    Current price $ 19.09
    $ 19.09 - $ 19.09
    Current price $ 19.09
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  • Original price $ 22.09
    Original price $ 22.09 - Original price $ 22.09
    Original price $ 22.09
    Current price $ 17.69
    $ 17.69 - $ 17.69
    Current price $ 17.69

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

    In stock

    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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    Original price $ 22.09
    Original price $ 22.09 - Original price $ 22.09
    Original price $ 22.09
    Current price $ 17.69
    $ 17.69 - $ 17.69
    Current price $ 17.69
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  • Original price $ 21.99
    Original price $ 21.99 - Original price $ 21.99
    Original price $ 21.99
    Current price $ 17.59
    $ 17.59 - $ 17.59
    Current price $ 17.59

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

    In stock

    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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    Original price $ 21.99
    Original price $ 21.99 - Original price $ 21.99
    Original price $ 21.99
    Current price $ 17.59
    $ 17.59 - $ 17.59
    Current price $ 17.59
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  • Original price $ 20.49
    Original price $ 20.49 - Original price $ 20.49
    Original price $ 20.49
    Current price $ 16.39
    $ 16.39 - $ 16.39
    Current price $ 16.39

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

    In stock

    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 — ...

    View full details
    Original price $ 20.49
    Original price $ 20.49 - Original price $ 20.49
    Original price $ 20.49
    Current price $ 16.39
    $ 16.39 - $ 16.39
    Current price $ 16.39
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