Skip to content
☀️ Take an Additional 10% Off Your Entire Order with code GEARUP10 at checkout.
☀️ Additional 10% Off • GEARUP10

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.

Filters

Foster BLH1B, 1/8" ISO-B Hydraulic Coupler x 1/8" Female NPT, ISO-B Series, Ball Lock, Brass Save 20% Save %
$ 246.00
$ 246.00 - $ 246.00
$ 246.00
$ 197.00
$ 197.00 - $ 197.00
$ 197.00

Foster 3003LV, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, Less Valve, Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3003LV is a Steel 1/4" industrial coupler from the Foster 3 Series — the m...

View full details
$ 246.00
$ 246.00 - $ 246.00
$ 246.00
$ 197.00
$ 197.00 - $ 197.00
$ 197.00
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 %
$ 346.00
$ 346.00 - $ 346.00
$ 346.00
$ 277.00
$ 277.00 - $ 277.00
$ 277.00

Foster 3003HW, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, Hot Water/Viton, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3003HW is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — th...

View full details
$ 346.00
$ 346.00 - $ 346.00
$ 346.00
$ 277.00
$ 277.00 - $ 277.00
$ 277.00
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 %
$ 291.00
$ 291.00 - $ 291.00
$ 291.00
$ 232.00
$ 232.00 - $ 232.00
$ 232.00

Foster 3003H, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, Heat/Viton, Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3003H is a Steel 1/4" industrial coupler from the Foster 3 Series — the mo...

View full details
$ 291.00
$ 291.00 - $ 291.00
$ 291.00
$ 232.00
$ 232.00 - $ 232.00
$ 232.00
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 %
$ 277.00
$ 277.00 - $ 277.00
$ 277.00
$ 221.00
$ 221.00 - $ 221.00
$ 221.00

Foster 3003D, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, Dill Valve, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3003D is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series — ...

View full details
$ 277.00
$ 277.00 - $ 277.00
$ 277.00
$ 221.00
$ 221.00 - $ 221.00
$ 221.00
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 %
$ 312.00
$ 312.00 - $ 312.00
$ 312.00
$ 249.00
$ 249.00 - $ 249.00
$ 249.00

Foster BL3003, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, Ball Lock, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BL3003 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series —...

View full details
$ 312.00
$ 312.00 - $ 312.00
$ 312.00
$ 249.00
$ 249.00 - $ 249.00
$ 249.00
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 %
$ 261.00
$ 261.00 - $ 261.00
$ 261.00
$ 209.00
$ 209.00 - $ 209.00
$ 209.00

Foster 3003, 1/4" Industrial Coupler x 1/4" Female NPT, 3 Series, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 3003 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series — t...

View full details
$ 261.00
$ 261.00 - $ 261.00
$ 261.00
$ 209.00
$ 209.00 - $ 209.00
$ 209.00
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
$ 324.00
$ 324.00 - $ 324.00
$ 324.00

Foster 2803W, 1/4" Industrial Coupler x 1/8" Female NPT, 3 Series, Water, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 2803W is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — the...

View full details
$ 404.00
$ 404.00 - $ 404.00
$ 404.00
$ 324.00
$ 324.00 - $ 324.00
$ 324.00
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 %
$ 1,037.00
$ 1,037.00 - $ 1,037.00
$ 1,037.00
$ 830.00
$ 830.00 - $ 830.00
$ 830.00

Foster 2803S/S, 1/4" Industrial Coupler x 1/8" Female NPT, 3 Series, 303 Stainless

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 2803S/S is a 303 Stainless 1/4" industrial coupler from the Foster 3 Serie...

View full details
$ 1,037.00
$ 1,037.00 - $ 1,037.00
$ 1,037.00
$ 830.00
$ 830.00 - $ 830.00
$ 830.00
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 %
$ 411.00
$ 411.00 - $ 411.00
$ 411.00
$ 329.00
$ 329.00 - $ 329.00
$ 329.00

Foster 2803S, 1/4" Industrial Coupler x 1/8" Female NPT, 3 Series, Steam/EPDM, Brass/SS

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 2803S is a Brass/SS 1/4" industrial coupler from the Foster 3 Series — the...

View full details
$ 411.00
$ 411.00 - $ 411.00
$ 411.00
$ 329.00
$ 329.00 - $ 329.00
$ 329.00
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 2803H, 1/4" Industrial Coupler x 1/8" Female NPT, 3 Series, Heat/Viton, Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 2803H is a Steel 1/4" industrial coupler from the Foster 3 Series — the mo...

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 %
$ 339.00
$ 339.00 - $ 339.00
$ 339.00
$ 272.00
$ 272.00 - $ 272.00
$ 272.00

Foster BL2803, 1/4" Industrial Coupler x 1/8" Female NPT, 3 Series, Ball Lock, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster BL2803 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series —...

View full details
$ 339.00
$ 339.00 - $ 339.00
$ 339.00
$ 272.00
$ 272.00 - $ 272.00
$ 272.00
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 %
$ 334.00
$ 334.00 - $ 334.00
$ 334.00
$ 266.00
$ 266.00 - $ 266.00
$ 266.00

Foster 2803, 1/4" Industrial Coupler x 1/8" Female NPT, 3 Series, Brass/Steel

Reliable, leak-free 1/4" connections for air and fluid lines. The Foster 2803 is a Brass/Steel 1/4" industrial coupler from the Foster 3 Series — t...

View full details
$ 334.00
$ 334.00 - $ 334.00
$ 334.00
$ 266.00
$ 266.00 - $ 266.00
$ 266.00
Save 20% Save %

Request a Quote

Bulk and dealer pricing. Tell us what you need and we’ll reply within one business day.