Threaded Fittings

Threaded Fittings & Thread Connectors

Our Online Store offers more than 100 configurations of threaded plastic tube fittings and connectors to join tubing to commonly used threaded ports, including tapered and straight threads. We also offer custom solutions. Contact us to discuss your application.

Threaded Fittings Technical Information

  • Nylon
  • Polypropylene
  • Polyvinylidene difluoride (PVDF)
  • Straight
  • Elbow
  • Tee
Thread Styles
  • 10-32 UNF
  • 1/16 – 27 NPT
  • 1/8 – 27 NPT
  • 1/4 – 18 NPT
  • 1/4 – 28 UNF
  • 5 x .8 metric
  • 6 x 1 metric
  • Bottom-sealing
  • Other special thread types
Connector Styles
  • Plastic panel-mount connectors and bulkhead fittings
  • Thread-to-barb fittings
  • Threaded elbow connectors
  • Threaded tee fittings
  • Straight reducers, plugs, and couplers

Thread Styles

Nordson MEDICAL offers five series (X, K, B, C, D) of tube connectors with threads. Available threads include:

  • 10-32 UNF
  • 1/4 - 28 UNF
  • 1/16 - 27 NPT
  • 1/8 - 27 NPT
  • 5 x .8
  • 6 x 1

The "X" Thread

Nordson MEDICAL X Series components have a tapered 10-32 thread that functions like a pipe thread. In comparison to standard 10-32 UNF threaded fittings, the tapered design works better with oversized ports and ports which are not perpendicular to the face of the component.

The 120° chamfer under the hex provides a seal when the fitting is tightened into a port with a countersink as shown below. It also seals on the thread due to interference on the pitch diameter. When using an elbow or tee, the tapered thread tightens radially and facilitates directional alignment of the barb.

Other Thread Series

Our K, B, C and D Series fittings, designed for use with 10-32 UNF ports, are straight-threaded components. These fittings seal against the 120 degree chamfer under the hex on the fitting, and do not tighten radially as they are assembled. Our S Series fittings are straight threaded components for 1/4-28 UNF ports, our M5 Series are for M5 x .8 ports and our M6 Series are for M6 x 1 ports.

Thread Features

The features shown here must be incorporated into the port when using our B, C, D, X, K, S, M5 and M6 Series fittings (see chart below). Failure to do so will jeopardize the performance of the seal between the fitting and port. For applications in which this seal is highly critical, we recommend that you contact a sealant specialist.

Thread Features

Nordson MEDICAL Thread Series Dimension A Minimum Full Thread Length Dimension B Countersink Diameter Feature C Internal Screw Thread Series
X .250" .210" - .230" 10-32 UNF 2B
K, B, C, D .200" .210" - .230" 10-32 UNF 2B
S .250" .270" - .290" 1/4-28 UNF 2B
M6 .375" .270" - .290" M6 x 1
M5 .250" .210" - .230" M5 x .8


Threaded Fittings Coupler

10-32 UNF threaded couplers, 1/4-28 UNF bottom sealing thread tube end couplers, and 10-32 special tapered thread couplers.


Threaded Fittings Plug

Thread plugs with 1/16-27 NPT, 1/8-27 NPT, 10-32 UNF, 1/4-28 UNF, M6x1, and 10-32 special tapered ports.

Straight Reducer

Threaded Fittings Straight Reducer

Reducers with 1/4-18 NPT or 1/8-27 NPT male threads to 10-32 UNF or 1/4-28 UNF female threads.

Thread to Barb

Threaded Fittings Thread to Barb

Thread to barb fittings with 1/16-27 and 1/8-27 NPT, 1/4-28 and 10-32 UNF, M5x.8, M6x1, and 10-32 special tapered thread ports.

Threaded Elbow

Threaded Fittings Elbow

Threaded elbow fittings with 1/8-27 NPT, 10-32 UNF, and 10-32 special tapered thread elbow ports.

Threaded Tee

Threaded Fittings Tee

1/8-27 NPT thread tees, 10-32 UNF thread tees, and 10-32 special tapered thread tees.

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