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Foster ISO-B Series Couplers

Foster ISO-B (FHK) Series hydraulic quick couplers and plugs, compatible with ISO 7241-1 Series B — the most widely used industrial hydraulic interchange. Two-way shut-off seals both halves at disconnect to prevent fluid loss and air inclusion. Manual sleeve connection at zero pressure. Body sizes 1/8" to 1", in RoHS-plated steel, brass, and 303/316 stainless with Buna-N seals.

  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
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    $ 25.49
    $ 25.49 - $ 25.49
    $ 25.49
    $ 20.39
    $ 20.39 - $ 20.39
    $ 20.39

    Foster K2S/SLV, 1/4" ISO-B Hydraulic Plug x 1/4" Female NPT, ISO-B Series, Less Valve, 303 Stainless Steel

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K2S/SLV is a 303 stainless steel 1/4" plug ...

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    $ 25.49
    $ 25.49 - $ 25.49
    $ 25.49
    $ 20.39
    $ 20.39 - $ 20.39
    $ 20.39
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  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
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    $ 16.29
    $ 16.29 - $ 16.29
    $ 16.29
    $ 12.99
    $ 12.99 - $ 12.99
    $ 12.99

    Foster K2S6, 1/4" ISO-B Hydraulic Plug x 9/16"-18 SAE, ISO-B Series, Plated Steel

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K2S6 is a plated steel 1/4" plug from the I...

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    $ 16.29
    $ 16.29 - $ 16.29
    $ 16.29
    $ 12.99
    $ 12.99 - $ 12.99
    $ 12.99
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  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
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    $ 11.49
    $ 11.49 - $ 11.49
    $ 11.49
    $ 9.19
    $ 9.19 - $ 9.19
    $ 9.19

    Foster K2SLV, 1/4" ISO-B Hydraulic Plug x 1/4" Female NPT, ISO-B Series, Less Valve, Plated Steel

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K2SLV is a plated steel 1/4" plug from the ...

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    $ 11.49
    $ 11.49 - $ 11.49
    $ 11.49
    $ 9.19
    $ 9.19 - $ 9.19
    $ 9.19
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  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
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    $ 18.19
    $ 18.19 - $ 18.19
    $ 18.19
    $ 14.59
    $ 14.59 - $ 14.59
    $ 14.59

    Foster K3B, 3/8" ISO-B Hydraulic Plug x 3/8" Female NPT, ISO-B Series, Brass

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K3B is a brass 3/8" plug from the ISO-B Ser...

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    $ 18.19
    $ 18.19 - $ 18.19
    $ 18.19
    $ 14.59
    $ 14.59 - $ 14.59
    $ 14.59
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  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
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    $ 24.39
    $ 24.39 - $ 24.39
    $ 24.39
    $ 19.59
    $ 19.59 - $ 19.59
    $ 19.59

    Foster K3B-101, 3/8" ISO-B Hydraulic Plug x 3/8" Female NPT, ISO-B Series, Viton Seal, Brass

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K3B-101 is a brass 3/8" plug from the ISO-B...

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    $ 24.39
    $ 24.39 - $ 24.39
    $ 24.39
    $ 19.59
    $ 19.59 - $ 19.59
    $ 19.59
    Save 20% Save %
  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
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    $ 23.79
    $ 23.79 - $ 23.79
    $ 23.79
    $ 19.09
    $ 19.09 - $ 19.09
    $ 19.09

    Foster K3B-102, 3/8" ISO-B Hydraulic Plug x 3/8" Female NPT, ISO-B Series, Neoprene Seal, Brass

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K3B-102 is a brass 3/8" plug from the ISO-B...

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    $ 23.79
    $ 23.79 - $ 23.79
    $ 23.79
    $ 19.09
    $ 19.09 - $ 19.09
    $ 19.09
    Save 20% Save %
  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
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    $ 22.29
    $ 22.29 - $ 22.29
    $ 22.29
    $ 17.89
    $ 17.89 - $ 17.89
    $ 17.89

    Foster K3B-103, 3/8" ISO-B Hydraulic Plug x 3/8" Female NPT, ISO-B Series, EPDM Seal, Brass

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K3B-103 is a brass 3/8" plug from the ISO-B...

    View full details
    $ 22.29
    $ 22.29 - $ 22.29
    $ 22.29
    $ 17.89
    $ 17.89 - $ 17.89
    $ 17.89
    Save 20% Save %
  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
    Save 20% Save %
    $ 16.59
    $ 16.59 - $ 16.59
    $ 16.59
    $ 13.29
    $ 13.29 - $ 13.29
    $ 13.29

    Foster K3S, 3/8" ISO-B Hydraulic Plug x 3/8" Female NPT, ISO-B Series, Plated Steel

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K3S is a plated steel 3/8" plug from the IS...

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    $ 16.59
    $ 16.59 - $ 16.59
    $ 16.59
    $ 13.29
    $ 13.29 - $ 13.29
    $ 13.29
    Save 20% Save %
  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
    Save 20% Save %
    $ 20.99
    $ 20.99 - $ 20.99
    $ 20.99
    $ 16.79
    $ 16.79 - $ 16.79
    $ 16.79

    Foster K3S-101, 3/8" ISO-B Hydraulic Plug x 3/8" Female NPT, ISO-B Series, Viton Seal, Plated Steel

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K3S-101 is a plated steel 3/8" plug from th...

    View full details
    $ 20.99
    $ 20.99 - $ 20.99
    $ 20.99
    $ 16.79
    $ 16.79 - $ 16.79
    $ 16.79
    Save 20% Save %
  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
    Save 20% Save %
    $ 20.29
    $ 20.29 - $ 20.29
    $ 20.29
    $ 16.19
    $ 16.19 - $ 16.19
    $ 16.19

    Foster K3S-102, 3/8" ISO-B Hydraulic Plug x 3/8" Female NPT, ISO-B Series, Neoprene Seal, Plated Steel

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K3S-102 is a plated steel 3/8" plug from th...

    View full details
    $ 20.29
    $ 20.29 - $ 20.29
    $ 20.29
    $ 16.19
    $ 16.19 - $ 16.19
    $ 16.19
    Save 20% Save %
  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
    Save 20% Save %
    $ 19.79
    $ 19.79 - $ 19.79
    $ 19.79
    $ 15.79
    $ 15.79 - $ 15.79
    $ 15.79

    Foster K3S-103, 3/8" ISO-B Hydraulic Plug x 3/8" Female NPT, ISO-B Series, EPDM Seal, Plated Steel

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K3S-103 is a plated steel 3/8" plug from th...

    View full details
    $ 19.79
    $ 19.79 - $ 19.79
    $ 19.79
    $ 15.79
    $ 15.79 - $ 15.79
    $ 15.79
    Save 20% Save %
  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
    Save 20% Save %
    $ 20.49
    $ 20.49 - $ 20.49
    $ 20.49
    $ 16.39
    $ 16.39 - $ 16.39
    $ 16.39

    Foster K3S-104, 3/8" ISO-B Hydraulic Plug x 3/8" Female NPT, ISO-B Series, Silicone Seal, Plated Steel

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K3S-104 is a plated steel 3/8" plug from th...

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    $ 20.49
    $ 20.49 - $ 20.49
    $ 20.49
    $ 16.39
    $ 16.39 - $ 16.39
    $ 16.39
    Save 20% Save %
  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
    Save 20% Save %
    $ 40.59
    $ 40.59 - $ 40.59
    $ 40.59
    $ 32.49
    $ 32.49 - $ 32.49
    $ 32.49

    Foster K3S/S, 3/8" ISO-B Hydraulic Plug x 3/8" Female NPT, ISO-B Series, 303 Stainless Steel

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K3S/S is a 303 stainless steel 3/8" plug fr...

    View full details
    $ 40.59
    $ 40.59 - $ 40.59
    $ 40.59
    $ 32.49
    $ 32.49 - $ 32.49
    $ 32.49
    Save 20% Save %
  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
    Save 20% Save %
    $ 45.09
    $ 45.09 - $ 45.09
    $ 45.09
    $ 35.99
    $ 35.99 - $ 35.99
    $ 35.99

    Foster K3S/S-101, 3/8" ISO-B Hydraulic Plug x 3/8" Female NPT, ISO-B Series, Viton Seal, 303 Stainless Steel

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K3S/S-101 is a 303 stainless steel 3/8" plu...

    View full details
    $ 45.09
    $ 45.09 - $ 45.09
    $ 45.09
    $ 35.99
    $ 35.99 - $ 35.99
    $ 35.99
    Save 20% Save %
  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
    Save 20% Save %
    $ 44.89
    $ 44.89 - $ 44.89
    $ 44.89
    $ 35.89
    $ 35.89 - $ 35.89
    $ 35.89

    Foster K3S/S-103, 3/8" ISO-B Hydraulic Plug x 3/8" Female NPT, ISO-B Series, EPDM Seal, 303 Stainless Steel

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K3S/S-103 is a 303 stainless steel 3/8" plu...

    View full details
    $ 44.89
    $ 44.89 - $ 44.89
    $ 44.89
    $ 35.89
    $ 35.89 - $ 35.89
    $ 35.89
    Save 20% Save %
  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
    Save 20% Save %
    $ 24.59
    $ 24.59 - $ 24.59
    $ 24.59
    $ 19.69
    $ 19.69 - $ 19.69
    $ 19.69

    Foster K3S8, 3/8" ISO-B Hydraulic Plug x 3/4"-16 SAE, ISO-B Series, Plated Steel

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K3S8 is a plated steel 3/8" plug from the I...

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    $ 24.59
    $ 24.59 - $ 24.59
    $ 24.59
    $ 19.69
    $ 19.69 - $ 19.69
    $ 19.69
    Save 20% Save %
  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
    Save 20% Save %
    $ 16.59
    $ 16.59 - $ 16.59
    $ 16.59
    $ 13.29
    $ 13.29 - $ 13.29
    $ 13.29

    Foster K3SLV, 3/8" ISO-B Hydraulic Plug x 3/8" Female NPT, ISO-B Series, Less Valve, Plated Steel

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K3SLV is a plated steel 3/8" plug from the ...

    View full details
    $ 16.59
    $ 16.59 - $ 16.59
    $ 16.59
    $ 13.29
    $ 13.29 - $ 13.29
    $ 13.29
    Save 20% Save %
  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
    Save 20% Save %
    $ 26.69
    $ 26.69 - $ 26.69
    $ 26.69
    $ 21.39
    $ 21.39 - $ 21.39
    $ 21.39

    Foster K4B, 1/2" ISO-B Hydraulic Plug x 1/2" Female NPT, ISO-B Series, Brass

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K4B is a brass 1/2" plug from the ISO-B Ser...

    View full details
    $ 26.69
    $ 26.69 - $ 26.69
    $ 26.69
    $ 21.39
    $ 21.39 - $ 21.39
    $ 21.39
    Save 20% Save %
  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
    Save 20% Save %
    $ 34.29
    $ 34.29 - $ 34.29
    $ 34.29
    $ 27.49
    $ 27.49 - $ 27.49
    $ 27.49

    Foster K4B-101, 1/2" ISO-B Hydraulic Plug x 1/2" Female NPT, ISO-B Series, Viton Seal, Brass

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K4B-101 is a brass 1/2" plug from the ISO-B...

    View full details
    $ 34.29
    $ 34.29 - $ 34.29
    $ 34.29
    $ 27.49
    $ 27.49 - $ 27.49
    $ 27.49
    Save 20% Save %
  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
    Save 20% Save %
    $ 33.39
    $ 33.39 - $ 33.39
    $ 33.39
    $ 26.79
    $ 26.79 - $ 26.79
    $ 26.79

    Foster K4B-102, 1/2" ISO-B Hydraulic Plug x 1/2" Female NPT, ISO-B Series, Neoprene Seal, Brass

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K4B-102 is a brass 1/2" plug from the ISO-B...

    View full details
    $ 33.39
    $ 33.39 - $ 33.39
    $ 33.39
    $ 26.79
    $ 26.79 - $ 26.79
    $ 26.79
    Save 20% Save %
  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
    Save 20% Save %
    $ 32.19
    $ 32.19 - $ 32.19
    $ 32.19
    $ 25.79
    $ 25.79 - $ 25.79
    $ 25.79

    Foster K4B-103, 1/2" ISO-B Hydraulic Plug x 1/2" Female NPT, ISO-B Series, EPDM Seal, Brass

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K4B-103 is a brass 1/2" plug from the ISO-B...

    View full details
    $ 32.19
    $ 32.19 - $ 32.19
    $ 32.19
    $ 25.79
    $ 25.79 - $ 25.79
    $ 25.79
    Save 20% Save %
  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
    Save 20% Save %
    $ 27.69
    $ 27.69 - $ 27.69
    $ 27.69
    $ 22.19
    $ 22.19 - $ 22.19
    $ 22.19

    Foster K4BLV, 1/2" ISO-B Hydraulic Plug x 1/2" Female NPT, ISO-B Series, Less Valve, Brass

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K4BLV is a brass 1/2" plug from the ISO-B S...

    View full details
    $ 27.69
    $ 27.69 - $ 27.69
    $ 27.69
    $ 22.19
    $ 22.19 - $ 22.19
    $ 22.19
    Save 20% Save %
  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
    Save 20% Save %
    $ 21.49
    $ 21.49 - $ 21.49
    $ 21.49
    $ 17.19
    $ 17.19 - $ 17.19
    $ 17.19

    Foster K4S, 1/2" ISO-B Hydraulic Plug x 1/2" Female NPT, ISO-B Series, Plated Steel

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K4S is a plated steel 1/2" plug from the IS...

    View full details
    $ 21.49
    $ 21.49 - $ 21.49
    $ 21.49
    $ 17.19
    $ 17.19 - $ 17.19
    $ 17.19
    Save 20% Save %
  • Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass
    Save 20% Save %
    $ 26.79
    $ 26.79 - $ 26.79
    $ 26.79
    $ 21.49
    $ 21.49 - $ 21.49
    $ 21.49

    Foster K4S-101, 1/2" ISO-B Hydraulic Plug x 1/2" Female NPT, ISO-B Series, Viton Seal, Plated Steel

    In stock

    Reliable, leak-free hydraulic connections built to the most widely used industrial standard. The Foster K4S-101 is a plated steel 1/2" plug from th...

    View full details
    $ 26.79
    $ 26.79 - $ 26.79
    $ 26.79
    $ 21.49
    $ 21.49 - $ 21.49
    $ 21.49
    Save 20% Save %