Bridging the gap between volume injection moulded parts and machined parts is something we’re faced with quite often. Injection moulded parts typically have a low unit cost but a very high setup and tooling cost, whilst machined parts have lower setup costs but generally longer cycle times.

Within both AFT and SW Plastics we have been manufacturing machined PEEK connectors, primarily for the oil tool market for some time. However, we were recently approached by a world-leading aerospace component manufacturer asking for help with their connectors.


Their problem was nothing new really. The injection moulding tools had reached the end of their service life and the volume requirements of the components had now dropped from OEM production of thousands, to spares and repair of only some hundreds per year.

And to add another complication, there were a lot of variants, meaning that simply replacing the injection moulding tooling was out of the question.


When we undertook an initial review of the components, we found they were going to be very involved to machine from solid (typical of injection moulded parts). This wouldn’t have been an impossible task, but it would be time consuming and expensive.

Obviously the client was looking for a fast and cost-effective solution.

Not being happy to ever decline an opportunity, we jumped on a plane and went to talk about it with their design, engineering and purchasing teams.

We had to open by stating no aspect of the initial remit could be adhered to (we didn’t end the conversation there however!). The customer had a strict material specification which was only suitable for injection moulding. They also had exact drawing specifications which were near impossible to machine, and a unit cost which was based on historic mass production levels.


By working in reverse from their end goal and dissecting the component aspects in great detail with them, we were sent off knowing what we had to do – well nearly!

Utilising our technical materials database, we were able to identify an alternative to their specification that had physical properties which almost exactly matched what was required. The main advantage of this alternative was its availability in semi-finished form to be machined.

Next we brainstormed the series of components, determining what detail was:

  • Critical to function
  • To aid injection moulding process
  • Purely for aesthetic reasons

We then continued this process with our production technicians until we had effectively redesigned the components so they could be efficiently manufactured whilst keeping the full functionality intact.

Jumping forward 12 months, we are machining all of these connector categories for this client and additionally, some of their new products are being designed around our input and manufacturing resource.   This has helped them mitigate the requirement for injection moulded parts for medium volume requirements.

If you’re having an issue in your aerospace business that you need a bespoke solution for, please get in touch.


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