How To Install PTFE Hose Fittings

Install Teflon hose fittings

Teflon hose assembly

Let us show you how to install PTFE hose fittings with our detailed step by step guide. This is taken from our Free to download eBook titled AN Hose & Fitting Guide.


What we show in this article can be used when installing aluminium PTFE hose fittings, ENS PTFE hose fittings and stainless steel PTFE hose fittings.

Teflon hose fittings

On this page – How To Install PTFE Hose Fittings – we cover the following:

  • Tools required
  • Step by step installation guide

Tools Required

If you are involved with modifying or building vehicles you will probably already have this equipment.

  • Bench mounted vice
  • Imperial sized spanners with a polished face to avoid marking the anodised finish
  • Light oil, 3 in 1 or similar
  • Fine tooth saw such as junior hacksaw
  • Small screwdriver or pick
  • Masking tape
  • Pliers and snips
  • Hobby knife
  • Personal Protective Equipment (gloves and glasses)
  • Cloth to wipe off excess oil
  • Vice Jaws. Speedflow will supply these free of charge with hose fitting orders over £60.00 net

How To Install PTFE Hose Fittings – Step by Step Installation Guide

This is a step by step guide that shows you precisely what to do. Follow these steps to have your PTFE hose fittings installed just like a Pro.

Step 1 – Cutting PTFE Hose

First we need to mark the cut position on the PTFE hose. To do this we wrap a piece of masking tape around the hose to cover the cut we are going to make. This serves two purposes, #1 to allow a pencil mark to be made in the exact position and #2 it will stop the stainless steel braid from flaring out as we cut.

Most people assembling hoses at home will use a fine tooth metal saw to cut the hose, it’s the sort of tool you’ll already have. You could use hose shears or other commercial hose cutting equipment if you have access to it.

Secure the hose before cutting in the plastic vice jaws. Cut square and let the saw blade do the cutting – do not force it. To install the PTFE hose fittings you will need to clean away any burrs from the PTFE tube. Any frayed stainless steel braids may be trimmed with snips.

Install Teflon hose fittings, cutting Teflon hose

Step 2

We are now going to fit the PTFE hose fitting socket nut on to the PTFE hose. But first we should check the hose is round by gently squeezing with pliers. We also insert the PTFE hose fitting at this time as a check that the i.d. is round – remove it and put it to one side. Before removing the masking tape, slide the socket nut onto the PTFE hose. Be sure it’s the correct way around.

install Teflon hose fittings, socket nut on Teflon hose

 Step 3 – Flaring The Braid

Using a small screwdriver or pick, gentle expand the stainless steel braid away from the PTFE tube. Work all around the tube until done. Care should be taken to ensure the PTFE hose is not damaged.

Installing Teflon hose fittings, flaring the stainless steel braid

 Step 4 – Installing the Olive / Ferrule

Push the olive / ferrule onto the end of the PTFE tube and under the stainless steel braid. Ensure no braid lies between the tube and the olive / ferrule. This is important because it is not possible to install PTFE hose fittings and have a leak free seal if a piece of braid is caught beneath the olive. Complete the installation by pressing the end of the olive / ferrule against a flat surface. Inspect to ensure the PTFE tube butts up squarely and fully against the inside shoulder of the olive / ferrule.

Install Teflon hose fittings, fitting the olive

 Step 5

Lubricate the threads on the socket nut, the hose end and also lubricate the PTFE hose fitting nipple using light oil. Insert the PTFE hose fitting into the PTFE hose by holding the hose and pushing the hose end nipple into the tube with a combined twisting pushing action. Check it is in as far as it will go.

Install Teflon hose fittings

Step 6

Hold the socket nut in the vice jaws and, keeping the assembly square, start to engage the socket and PTFE hose fitting thread. It will be possible to start the threads by hand and to be sure the threads are correctly aligned.

install Teflon hose fittings, tighten socket nut

Step 7

Using the correct size spanner, tighten the PTFE hose fitting into the socket nut. Apply oil to the thread as you tighten up the union. Continue to tighten the PTFE hose fitting into the socket until you have a gap of approximately 1mm. Align the flats for a professional finish.

Install Teflon hose fittings


If you re-use or disassemble a PTFE hose fitting the olive / ferrule must be changed for new. The olive / ferrule can only be used once

Useful Information

Speedflow does not and never has charged to install PTFE hose fittings with parts and hose purchased from Speedflow Products Limited.

Please visit the Speedflow on line shop for PTFE Hose, Aluminium PTFE hose fittings, ENS PTFE hose fittings or Stainless Steel PTFE hose fittings.

We hope you found this article useful. This and lots more information about AN Hose and Fittings can be found in our free to download eBook – just click on the link to get your copy.