Skip to content
3H21 Hansen® by Danfoss | Quick Disconnect Coupling | HK1-8 Series | 3/8" Female NPTF x 3/8" ISO 7241-1 B | Socket | NBR Seal | Steel

3H21 Hansen® by Danfoss | Quick Disconnect Coupling | HK1-8 Series | 3/8" Female NPTF x 3/8" ISO 7241-1 B | Socket | NBR Seal | Steel

$0.00 - $0.00
$0.00
$32.55
$32.55 - $32.55
$32.55

Hansen® by Danfoss
HK Series | ISO 7241-1 B Interchange

Fluid Transfer and Hydraulic Quick Disconnect Coupling

Danfoss Hansen HK Series coupling sets the industry standard for ISO B Couplings.

The HK Series features a rugged ball latch mechanism with automatic self-sealing poppet valves in a wide array of port configurations and multiple valved and non-valved configurations.
Can I get a discount on my purchase?

Our listed prices are our lowest possible price with current costing but when volumes/value are high enough sometimes we can pass on a discount from the manufacturer.

Some products have predefined quantity discounts that will apply automatically, those pages have a table near the price describing the discount teirs.

If you feel your purchase quantity of a particular product is very large and want us to investigate with the manufacturer please feel free to Contact Us.

What if my item is out of stock?

All customers get an email regarding the shipping time frame of their purchase, usually within the business day. If your item is in stock we will ship within 1 business day, otherwise, the email will contain a lead time. If you do not receive this email, we recommend checking your email's spam folder. If you have any questions at that point please do not hesitate to Contact Us or chat below!

Can I get free shipping?

Shipping will calculate as free instantly if your order value exceeds $5000.

Some exceptions apply.

Free Freight is only available for the Contiguous USA.

Specifications for Variant SKU: 3H21 Danfoss
Brand: Hansen
Series: HK1-8 Series
Shape (Orientation): Straight
Ends Configuration: 3/8in Female NPTF, 3/8in ISO-B QD Interchange
Material(s): Steel
Seal Material(s): Buna-N/Nitrile Rubber
Product Features:
  • The coupling that sets the industry standard.
  • Self-sealing poppet valve design provides excellent high and low pressure sealing.
Applications & Markets:
  • Agriculture
  • Hydraulic Tool
  • General Industry
  • Construction
  • Fluid Transfer
  • Transportation
  • Military
  • Law Enforcement/Rescue
  • Chemical
  • Oil and Gas
  • Consumer Products
  • HVAC
  • Food and Beverage
  • Trucks
  • Aerospace
  • Medical
ISO Standard:
  • Meets dimensional requirements to ISO standard 7241-1 Series B.
Materials:
  • Standard body material: Zinc trivalent plated steel with stainless steel springs, balls and retaining rings.
  • Standard seal material: Nitrile (NBR) (Max. Operating Temp: 40°F to +250°F | -40°C to +121°C).
  • PTFE back up rings in sockets (females).
European Pressure Equipment Directive:
  • Couplings with nominal diameters up to and including 25 mm are designed and manufactured under Article 4.3 of the European Pressure Equipment Directive 2014/68/EU. Couplings with nominal diameters greater than 25 mm are designed and manufactured in accordance with stipulations of Module A of the European Pressure Equipment Directive 2014/68/EU. They should not be used to convey unstable gases.

Group 1 = Hazardous media / Group 2 = Other media

Series Body Size ISO Size Nominal Flow
Diameter		 Max. Operating
Pressure		 Rated
Flow*		 Air
Inclusion		 Fluid
Loss
Non Hazardous
Liquids & Gases
(Group 2)		 Hazardous
Liquids & Gases
(Group 1)
in. mm mm bar psi bar psi lpm gpm cc.max. cc.max.
1HK 1/8" 5mm 4.4mm 275 bar 4,000 psi 275 bar 4,000 psi 3 lpm 0.8 gpm 0.6 cc.max. 0.5 cc.max.
2HK 1/4" 6.3mm 5.9mm 345 bar 5,000 psi 345 bar 5,000 psi 12 lpm 3 gpm 1.2 cc.max. 0.9 cc.max.
3HK 3/8" 10mm 7.8mm 275 bar 4,000 psi 275 bar 4,000 psi 23 lpm 6 gpm 2.9 cc.max. 2.1 cc.max.
4HK 1/2" 12.5mm 10mm 345 bar 5,000 psi 345 bar 5,000 psi 45 lpm 12 gpm 3.6 cc.max. 3.5 cc.max.
6HK 3/4" 20mm 17mm 275 bar 4,000 psi 275 bar 4,000 psi 100 lpm 26 gpm 11.5 cc.max. 9.3 cc.max.
8HK 1" 25mm 19.6mm 275 bar 4,000 psi 275 bar 4,000 psi 189 lpm 50 gpm 18.0 cc.max. 16.9 cc.max.
10HK 1-1/4"** - 26.7mm 200 bar 2900 psi 37 bar 537 psi 288 lpm 76 gpm 48.0 cc.max. 48.0 cc.max.
12HK 1-1/2" 40mm 35.1mm 150 bar 2175 psi 29 bar 421 psi 375 lpm 99 gpm 91.3 cc.max. 91.3 cc.max.
20HK 2-1/2" 50mm 46mm 100 bar 1450 psi 21 bar 305 psi 757 lpm 200 gpm 209.9 cc.max. 209.9 cc.max.

For questions related to vacuum please contact Danfoss.
** No ISO Standard available for the 10HK
Socket/Female (Figure 1)
Plugs (Male) (Figure 2)
HK1-8 Series
Part Number Body Size ISO
Size		 Type Female
Thread		 Figure Dimensions
NBR Seal A B Across
Flats		 C D E Hex
1H11 1/8" 5mm Socket/Female 1/8-27 Fem. NPTF 1 1.91"
(48.5mm)		 0.98"
(24.9mm)		 0.56"
(14.2mm)		 - - - -
1K11 1/8" 5mm Plug/Male 1/8-27 Fem. NPTF 2 - - - 1.26"
(32.0mm)		 0.65"
(16.5mm)		 0.44"
(11.2mm)		 0.56"
(14.2mm)
1H4 1/8" 5mm Socket/Female 7/16-20 Fem. SAE ORB 1 2.06"
(52.3mm)		 0.98"
(24.9mm)		 0.69"
(17.5mm)		 - - - -
1K4 1/8" 5mm Plug/Male 7/16-20 Fem. SAE ORB 2 - - - 1.41"
(35.8mm)		 0.79"
(20.1mm)		 0.59"
(15.0mm)		 0.69"
(17.5mm)
2H16 1/4" 6.3mm Socket/Female 1/4-18 Fem. NPTF 1 2.26"
(57.4mm)		 1.14"
(29.0mm)		 0.75"
(19.1mm)		 - - - -
2K16 1/4" 6.3mm Plug/Male 1/4-18 Fem. NPTF 2 - - - 1.52"
(38.6mm)		 0.87"
(22.1mm)		 0.56"
(14.2mm)		 0.75"
(19.1mm)
2H16BS 1/4" 6.3mm Socket/Female 1/4-19 Fem. BSPP 1 2.31"
(58.7mm)		 1.14"
(29.0mm)		 0.75"
(19.1mm)		 - - - -
2K16BS 1/4" 6.3mm Plug/Male 1/4-19 Fem. BSPP 2 - - - 1.52"
(38.6mm)		 0.87"
(22.1mm)		 0.56"
(14.2mm)		 0.75"
(19.1mm)
2H6 1/4" 6.3mm Socket/Female 9/16-18 Fem. SAE ORB 1 2.40"
(61.0mm)		 1.14"
(29.0mm)		 0.88"
(22.4mm)		 - - - -
2K6 1/4" 6.3mm Plug/Male 9/16-18 Fem. SAE ORB 2 - - - 1.66"
(42.2mm)		 1.01"
(25.7mm)		 0.70"
(17.8mm)		 0.88"
(22.4mm)
3H21 3/8" 10mm Socket/Female 3/8-18 Fem. NPTF 1 2.56"
(65.0mm)		 1.42"
(36.1mm)		 0.88"
(22.4mm)		 - - - -
3K21 3/8" 10mm Plug/Male 3/8-18 Fem. NPTF 2 - - - 1.76"
(44.7mm)		 1.01"
(25.7mm)		 0.61"
(15.5mm)		 0.88"
(22.4mm)
3H21BS 3/8" 10mm Socket/Female 3/8-19 Fem. BSPP 1 2.56"
(65.0mm)		 1.42"
(36.1mm)		 0.88"
(22.4mm)		 - - - -
3K21BS 3/8" 10mm Plug/Male 3/8-19 Fem. BSPP 2 - - - 1.76"
(44.7mm)		 1.01"
(25.7mm)		 0.61"
(15.5mm)		 0.88"
(22.4mm)
3H8 3/8" 10mm Socket/Female 3/4-16 Fem. SAE ORB 1 2.74"
(69.6mm)		 1.42"
(36.1mm)		 1.00"
(25.4mm)		 - - - -
3K8 3/8" 10mm Plug/Male 3/4-16 Fem. SAE ORB 2 - - - 1.94"
(49.3mm)		 1.15"
(29.2mm)		 0.79"
(20.1mm)		 1.00"
(25.4mm)
4HP26 1/2" 12.5mm Socket/Female 1/2-14 Fem. NPTF 1 2.96"
(75.2mm)		 1.86"
(47.2mm)		 1.13"
(28.7mm)		 - - - -
4KP26 1/2" 12.5mm Plug/Male 1/2-14 Fem. NPTF 2 - - - 2.03"
(51.6mm)		 1.30"
(33.0mm)		 0.76"
(19.3mm)		 1.13"
(28.7mm)
4HP26BS 1/2" 12.5mm Socket/Female 1/2-14 Fem. BSPP 1 2.96"
(75.2mm)		 1.86"
(47.2mm)		 1.13"
(28.7mm)		 - - - -
4KP26BS 1/2" 12.5mm Plug/Male 1/2-14 Fem. BSPP 2 - - - 2.03"
(51.6mm)		 1.30"
(33.0mm)		 0.76"
(19.3mm)		 1.13"
(28.7mm)
4HP10 1/2" 12.5mm Socket/Female 7/8-14 Fem. SAE ORB 1 3.05"
(77.5mm)		 1.86"
(47.2mm)		 1.25"
(31.8mm)		 - - - -
4KP10 1/2" 12.5mm Plug/Male 7/8-14 Fem. SAE ORB 2 - - - 2.11"
(53.6mm)		 1.37"
(34.8mm)		 0.84"
(21.3mm)		 1.19"
(30.2mm)
6HP31 3/4" 20mm Socket/Female 3/4-14 Fem. NPTF 1 3.48"
(88.4mm)		 2.22"
(56.4mm)		 1.31"
(33.3mm)		 - - - -
6KP31 3/4" 20mm Plug/Male 3/4-14 Fem. NPTF 2 - - - 2.36"
(59.9mm)		 1.52"
(38.6mm)		 0.71"
(18.0mm)		 1.31"
(33.3mm)
6HP31BS 3/4" 20mm Socket/Female 3/4-14 Fem. BSPP 1 3.48"
(88.4mm)		 2.22"
(56.4mm)		 1.31"
(33.3mm)		 - - - -
6KP31BS 3/4" 20mm Plug/Male 3/4-14 Fem. BSPP 2 - - - 2.36"
(59.9mm)		 1.52"
(38.6mm)		 0.71"
(18.0mm)		 1.31"
(33.3mm)
6HP12 3/4" 20mm Socket/Female 1-1/16 Fem. SAE ORB 1 3.67"
(93.2mm)		 2.22"
(56.4mm)		 1.38"
(35.1mm)		 - - - -
6KP12 3/4" 20mm Plug/Male 1-1/16 Fem. SAE ORB 2 - - - 2.54"
(64.5mm)		 1.59"
(40.4mm)		 0.89"
(22.6mm)		 1.38"
(35.1mm)
8HP36 1" 25mm Socket/Female 1-11-1/2 Fem. NPTF 1 4.13"
(104.9mm)		 2.61"
(66.3mm)		 1.75"
(44.5mm)		 - - - -
8KP36 1" 25mm Plug/Male 1-11-1/2 Fem. NPTF 2 - - - 2.85"
(72.4mm)		 1.88"
(47.8mm)		 0.97"
(24.6mm)		 1.63"
(41.4mm)
8HP36BS 1" 25mm Socket/Female 1-11 Fem. BSPP 1 4.13"
(104.9mm)		 2.61"
(66.3mm)		 1.75"
(44.5mm)		 - - - -
8KP36BS 1" 25mm Plug/Male 1-11 Fem. BSPP 2 - - - 2.85"
(72.4mm)		 1.88"
(47.8mm)		 0.97"
(24.6mm)		 1.63"
(41.4mm)
8HP16 1" 25mm Socket/Female 1-5/16-12 Fem. SAE ORB 1 4.13"
(104.9mm)		 2.61"
(66.3mm)		 1.88"
(47.8mm)		 - - - -
8KP16 1" 25mm Plug/Male 1-5/16-12 Fem. 2 - - - 2.85"
(72.4mm)		 2.17"
(55.1mm)		 0.97"
(24.6mm)		 1.88"
(47.8mm)
HK10/12/20 Series
Socket/Female (Figure 3)
Plugs (Male) (Figure 4)
Part Number Body
Size		 ISO
Size		 Type Female
Thread		 Figure Dimensions
NBR Seal A B Hex C D E Hex
10H41* 1-1/4" - Socket/Female 1-1/4-11-1/2 Fem. NPTF 3 4.51"
(114.6mm)		 2.73"
(69.3mm)		 2.38"
(60.5mm)		 - - - -
10K41* 1-1/4" - Plug/Male 1-1/4-11-1/2 Fem. NPTF 4 - - - 4.25"
(108.0mm)		 2.74"
(69.6mm)		 2.33"
(59.2mm)		 2.38"
(60.5mm)
10H41BS* 1-1/4" - Socket/Female 1-1/4-11 Fem. BSPP 3 4.51"
(114.6mm)		 2.73"
(69.3mm)		 2.38"
(60.5mm)		 - - - -
12H41 1-1/2" 40mm Socket/Female 1-1/4-11-1/2 Fem. NPTF 3 4.82"
(122.4mm)		 3.23"
(82.0mm)		 2.38"
(60.5mm)		 - - - -
12K41 1-1/2" 40mm Plug/Male 1-1/4-11-1/2 Fem. NPTF 4 - - - 4.76"
(120.9mm)		 2.74"
(69.6mm)		 2.67"
(67.8mm)		 2.38"
(60.5mm)
12H46 1-1/2" 40mm Socket/Female 1-1/2-11-1/2 Fem. NPTF 3 4.82"
(122.4mm)		 3.23"
(82.0mm)		 2.38"
(60.5mm)		 - - - -
12K46 1-1/2" 40mm Plug/Male 1-1/2-11-1/2 Fem. NPTF 4 - - - 4.76"
(120.9mm)		 2.74"
(69.6mm)		 2.67"
(67.8mm)		 2.38"
(60.5mm)
12K46BS 1-1/2" 40mm Plug/Male 1-1/2-11 Fem. BSPP 4 - - - 4.76"
(120.9mm)		 2.74"
(69.6mm)		 2.67"
(67.8mm)		 2.38"
(60.5mm)
20H51 2-1/2" 50mm Socket/Female 2-11-1/2 Fem. NPTF 3 5.55"
(141.0mm)		 4.11"
(104.4mm)		 3.75"
(95.3mm)		 - - - -
20K51 2-1/2" 60mm Plug/Male 2-11-1/2 Fem. NPTF 4 - - - 5.49"
(139.4mm)		 4.33"
(110.0mm)		 2.97"
(75.4mm)		 3.75"
(95.3mm)
20H56 2-1/2" 50mm Socket/Female 2-1/2-8 Fem. NPTF 3 6.14"
(156.0mm)		 4.11"
(104.4mm)		 3.75"
(95.3mm)		 - - - -
20K56 2-1/2" 60mm Plug/Male 2-1/2-8 Fem. NPTF 4 - - - 6.08"
(154.4mm)		 4.33"
(110.0mm)		 3.56"
(90.4mm)		 3.75"
(95.3mm)
20H61 2-1/2" 50mm Socket/Female 3-8 Fem. NPTF 3 7.00"
(177.8mm)		 4.11"
(104.4mm)		 4.00"
(101.6mm)		 - - - -
20K61 2-1/2" 60mm Plug/Male 3-8 Fem. NPTF 4 - - - 6.94"
(176.3mm)		 4.62"
(117.3mm)		 4.42"
(112.3mm)		 4.00"
(101.6mm)

A=Overall Length, B=Maximum Diameter
* ISO 7241-1 Series B does not include 1-1/4 inch body size couplings; therefore, Series 10HK is not covered by this standard.
To obtain connected length of coupling, add dimensions A (Fig. 1) and E (Fig. 2) together.
To obtain connected length of coupling, add dimensions A (Fig. 3) and E (Fig. 4) together.

Danfoss (Eaton - Aeroquip)

Danfoss (Eaton - Aeroquip)

Danfoss is a global technology leader in power management solutions that make electrical, hydraulic and mechanical power operate more efficiently, reliably, safely and sustainably. Danfoss hydraulic pumps, motors, transmissions, valves, cylinders, controls, hose and fittings offer a unique combination of proven technology and innovative design that translates directly into reliable performance and enhanced uptime.

Shop Parts by Danfoss (Eaton - Aeroquip)