Should Tooling Fabrication and Plastic Injection Molding Be Done Together When you’re manufacturing your new product with injection molded parts or enclosures, the question about who is fabricating the molds is an important one to answer. Some tooling fabricators also provide plastic injection molding services in-house, but is this a good option for you? In some cases, manufacturers prefer to fabricate molds in China, export them, and then do the injection molding closer to home for numerous reasons. So, what are your options and what are the risks?



Option 1. Fabricate molds in China, but export them and do the molding elsewhere

With the talk of ‘de-risking’ supply chains and the specter of tariffs on China-made goods, especially for American businesses, it might seem to make sense to get your plastic injection mold tooling made in China, where it’s cheaper, but export them and do the molding of parts closer to home in the States. Doing the manufacturing work in the same country also has its appeal in terms of distance, control over the supply chain, communication, and more, so it’s understandable why some businesses like this idea.


In this case, you benefit in the following ways:

  • Enjoy the relatively low cost of the tooling which is a high cost for businesses.
  • Deal with local supplier in English who injection molds your parts at an, arguably, higher quality.
  • Ability to have more visibility over the products and inspect them locally yourself, also saving time and money.
  • Have fast lead times and shorter distances for shipping the products within the same country.
  • Reduce exposure to China risks and potentially be able to state that products are made locally.


By splitting the tooling fabrication and injection molding and having oceans between them, there are certain risks, though:

  • You select a toolmaker who has not export experience, then it’s all on you to get the tooling from A to B.
  • The largest risk is that the mold maker does the first shots off the tooling on a certain type of press, with certain settings, in certain environmental conditions (temperature, humidity, altitude… all have an impact), and that the North America-based plastic manufacturer finds it very hard to replicate that. This is not an uncommon problem, and we’ve seen examples where the mold was made in China, shipped to another country where the injection molding shop was unable to get good parts out of the tooling, and then the mold had to be shipped back to China for rework (which was neither cheap nor fast).
  • Regarding rework of the tooling during the first runs, molds may require subsequent visits back to the fabricator for them to polish, machine in certain details, etc. This becomes a really difficult situation if the molds require a transpacific journey every time.
  • If you do require rework on the mold and you want to do it in the USA, can your plastic manufacturer there even do the tooling rework in their own facility (and do they have the know-how to actually fabricate a mold)? How much will it cost? Will it then work with a 100% probability? There are a lot of unknowns here, and at the least, it might be prohibitively expensive.

You might also be able to find an American plastic supplier who has been getting tooling made in China before and has experience in handling the risks above. It’s possible that they can handle the whole process for you by sourcing from their trusted suppliers, at a higher cost, probably, but also with reduced risks for yourself. If they make mistakes leading to problems, be sure that a manufacturing contract was signed in advance that makes them accountable (this is not only a must when dealing with Chinese manufacturers and we’ll discuss contracts further in a moment).


Option 2. Fabricate molds in China and do injection molding there with the same supplier, too

Our recommended options for the reasons you’re about to find out…

Chinese tooling workshops are among the best and cheapest in the world. Why? Experience, speed, and the relatively low prices they can offer. Nowhere has the infrastructure and number of tooling fabricators that China has, and they have been producing high-quality molds of all types for decades.

We specifically recommend tooling workshops in the Shenzhen/Dongguan area rather than Ningbo (another common sourcing location) as their results tend to be better.

While it is possible to get tooling made and take it elsewhere, many of these workshops also include a plastic injection shop on-site, too, as the two services are so intertwined.

Logically, handling everything with one supplier and not shipping molds over the oceans before working with them makes sense in many ways.


There are some advantages to working with this type of ‘everything-under-one-roof’ tooling fabrication and plastic injection molding supplier:

  • You deal with just one organisation which can be smoother and less time-consuming than spinning several plates at one time with numerous suppliers, logistics, etc.
  • If there turns out to be problems with the tooling the buck stops with the supplier, they can’t blame a third-party injection molding shop because they’re the ones doing the molding! In fact, this is also less likely because the supplier knows their own machines and capabilities, and will fabricate their molds accordingly to have the lowest risks possible.
  • It may be easier to ask them to ‘amortise’ the tooling cost into the unit cost you pay because they control the whole process in-house… if that’s what you really want (note: in many cases, it’s not a great idea).


Here are some risks and general notes that you should pay attention to in this scenario:

  • You need to check that the company is not subcontracting any of the work to third parties…for instance, some might fabricate molds but then subcontract the plastic injection molding to a ‘friend’s’ factory. If so, do you know this third-party company? Can they produce the parts to your standards? Do they even know what your standards are? Are they using exactly the right materials? Can you visit and inspect them? If there are quality issues, who is responsible?
    As you can see, bringing another party into the mix is at best messy, and at worst, leaves you totally in the dark about who is in your supply chain and whether your products are even made at the correct level of quality or are even compliant to your market’s regulations.
  • If your molds end up being less than great, good plastic injection molding suppliers will refuse to work with them, but if your mold fabricator is also doing injection molding they won’t let that happen, as they’ll be confident that their mold is fine for the injection molding they’re going to subsequently be doing.
  • If the supplier is not bound by a legally enforceable manufacturing contract, you lack control over them and they might use this as an excuse to play dirty. For example, if they know they have total control over the tooling, they might suddenly play tricks like saying that ‘the parts are hard to make and there is a lot of scrap, so prices need to be increased by 30%.’ In this situation, what can you do? They hold your tooling hostage and you can’t pull it out and go elsewhere. Other issues include them subcontracting the injection molding to the cheapest most disorganized workshop, leading to quality issues for you, but higher profits for them. The same applies if, say, they decide to use 80% regrind material instead of virgin plastics.
    You must put in place a legally enforceable contract that they sign before you pay them anything that spells out that (1) all related IP rights belong to you and (2) you can pull out the tooling from their facility at any time for any reason, otherwise, you have no leverage over them and they might try and take advantage of you as discussed above.

Remember, if this tooling workshop is also going to be the injection molded parts supplier, you should ask for quotations for the plastic parts at the same time as getting quotes for the tooling itself, not later. Asking for both at the same time is quite typical and normal.

Pulling out t0oling isn’t always simple, but Sofeast provides a Tooling Custody & Management (In China) solution where we pick up or receive your tooling after a production run (noting what condition the tooling is in), store it securely, and then return it back to your supplier before the next run. In this way, the risks of your tooling being missed or damaged are minimized, and it’s also given a regular check (to our 90-point checklist) by our team.


Your Chinese tooling workshop needs to follow a validation plan

After you have found a suitable tooling workshop in China you will need to do proper validation. Having someone on the ground to confirm that the first parts off of tooling are acceptable dimension-wise, and shipping them to you for final validation (aesthetics-wise but also when assembling the different parts together), does not reduce your risk much, even if they jot down the exact settings, the machine model, etc.

What do I mean by proper validation?

It depends on how much risk you are comfortable accepting (based on the money involved, your tolerance for delays, your tolerance for small defects, etc.).
Here’s an example typical for relatively high-quality and high-volume part manufacturing:

Request the tooling shop to set up a 32-hour pilot run for each mold; after running for 16 hours, the mold has to be taken out of the machine for preventive maintenance and then later be put back into the machine to keep going; if the parts are out of tolerance at one point, the process has to be stopped and re-started.

The above validation work can be supervised, of course, and Sofeast has experience with doing this supervision. We offer a solution here: Mold Capability Validation Supervision (in China), where one of our technical engineers travels to your toolmaker’s workshop and supervises their validation of the mold’s capability, reporting back findings to you so any issues can be addressed by the supplier long before the mold is shipped out.

(Note: I’d guess 90% of Chinese tooling shops will refuse this type of validation plan, and the rest will charge extra to undertake this work. This example might be a bit too extreme for some overseas businesses’ needs.)


Further reading

You may also like these resources about tooling and plastic injection molding:

Remember, you can contact us anytime to discuss tooling, injection molding, or anything else manufacturing-related that’s on your mind!

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