What Should Be Included in an Injection Molding Agreement?

Most overseas buyers’ and manufacturers’ disputes are not about bad molding
parts. They begin with a contract that didn’t mention ownership of the mold, what the term "quality" meant in terms of measurable criteria, or what to do if either party wanted to pull out.

When a problem begins to appear, it’s typically too late to fix by telephone. The mold sits in a factory that has no legal reason to hand it over. Another competitor is offering an identical or closely matching part. The batch is rejected, and no one agreed beforehand what should be done next.

None of this requires a factory acting in bad faith. Most of it comes from an agreement that was too vague to answer the question when it mattered. In this article, you will learn what a good injection molding contract with a Chinese manufacturer¹ should include.

The information contained in this article is general information to assist buyers in their selection of suppliers and not a legal opinion. It’s always important to have a qualified lawyer who is well-versed in cross-border manufacturing agreements review any agreement before signing.

Two Different Contracts, Two Different Protections

It is important to break down two things before entering the clauses: components of the purchase that are often grouped.

NNN Agreement (Non-Disclosure, Non-Use, Non-Circumvention) safeguards your design and intellectual property. It’s created specifically for the Chinese manufacturing environment and, if drafted in accordance with Chinese legislation, can prove to be a valuable weapon if a factory copies your design, sells it to another customer, or ignores you and goes straight to your customers. A typical Western NDA, translated into Chinese, typically is not as protective.

A mold or tooling ownership agreement safeguards the physical asset. A document, or at least a distinct portion of the manufacturing agreement, that specifies ownership of the mold, its location, and the terms of its release.

Purchasers often sign one and believe it is applicable to both. It doesn’t. Two protections must be in place in writing before tooling work.

Part Specifications and Drawing Control in Injection Molding Agreement

The agreement should clearly specify the drawing revision that will be used for production and/or state which will govern if a 2D drawing and a 3D model ever differ. It should also indicate:

• Material Grade: Exactly (Not Just "nylon" or "ABS") Resin Type and Fill Percentage
• Cavity count
• Standard for surface finish (SPI or VDI grade)
• The change-control process: who needs to sign off on a design change, and who will cover the cost of the mould change?

Getting these specifications locked down early is really a Design for Manufacturing exercise — our breakdown of DFM principles in injection molding covers how drawing decisions made at this stage affect cost, cycle time, and mold life later on.

If it’s only a vague specification, it’s likely to be filled by the factory with the cheapest yet still reasonably sound items.

Do You Own a Complete Mold, or Just Inserts on a Shared Base?

Many buyers don’t realize this difference until it gets expensive for them. Some tooling quotes include an entire, complete, and self-contained mold. Others fill only the cavity inserts, which go into a base frame (also known as a MUD base, Master Unit Die) that the factory owns and reuses across various customers’ projects. You really have the inserts that you have paid for. However, if not in the environment for which they were designed, they’re practically worthless in another factory.

When getting a tooling quote, one of the first things to check is whether it’s suspiciously cheap compared to other quotes for the same part. Ask straight out: Does this price include a full mold that I can take to any skilled factory, or does it include inserts that only work in a base that you keep? This should be stated specifically in the agreement, not implied by the line item "tooling cost."

Mold Ownership: What the Clause Actually Needs to Say

Under Chinese law, paying for a mold does not necessarily make you the owner of the mold. Many first-time buyers are surprised at this. If no contract language specifies otherwise, the control will be held by the party with physical possession of the tool—which is nearly always the factory.

If you really want to be covered by an ownership clause, it must contain the following:

Explicit ownership language. Note clearly that the mold (with a particular mold number) belongs to the buyer, and the factory only has the use right of the buyer. Don’t soft-phrase it, such as "jointly invested" or "co-owned," as this opens the door to later making an argument.

Physical marking. The factory should put the buyer’s company name and mold identification on the tool itself, preferably in a permanent way in the form of an engraving or permanent plating. It will not prevent a determined factory on its own, but will help eliminate any confusion when they are on the shop floor. When a dispute does require documentation, it will then be clear which asset it is.

Right of removal, with real-time schedule. The agreement should give the buyer an unconditional right to receive the mold on request, with a fixed retrieval window, typically within 30 days after written notice is sent, and a liquidated damages clause in case the factory does not release the mold within that time. A weak "the mold will be released upon request" provision doesn’t have any bite without an explicit request by a deadline.

Storage, Maintenance, Insurance. The mold is kept at the factory between each order, and someone has to be responsible for maintaining it and keeping it insured against damage. This should be a specific task and not an assumption.

It’s also worth calling out a pricing pattern outright, as it helps you to explain why some quotes sound too good to be true. Others have very low tooling costs – often lower than the actual cost – because they believe the investment will be recouped over the next year or two of production. If the buyer removes the mould too early, the factory has really lost money on it, and this can sometimes be a bargaining chip to refuse to give it away or to ask for another fee, which in some cases is 15–30 per cent of the original tooling cost.

This doesn’t necessarily mean it’s a lie. It’s a common practice in Chinese manufacturing and is manageable if discussed and written into the agreement ahead of time: either the buyer agrees to pay for full recovery of the tooling price, no matter when the buyer leaves, or both sides agree to a written agreement about the recovery of the tooling price, and what’s owed, if the buyer leaves too early.

How to Prevent the Family Mold Trap

To reduce tooling costs, a family mold may be used to make two or more different parts, such as a family of top and bottom housings, in the same mold and the same cycle. It is efficient, and sometimes it is. The difficulty occurs when the volume of the parts is not equal. If you need twice as many bottom housings as top housings, you are still forced to run both parts on every cycle, so you end up sitting on excess stock of whichever one sells slower.

The typical family mold makes sense only with a good degree of similar demand. Best to discuss this directly in the quoting process, rather than finding the trade-off later, when the tool is already created.

Tooling Payment Milestones in Injection Molding Agreement

Calendar date terms of payment secure the factory. Payment terms based on a technical milestone safeguard the buyer. A structure in which both sides can see each other resembles the following:

• A deposit is paid on confirmation of the purchase order.
• A second payment is made on mold design approval.
• T1 sample approval – a third payment
• Balances after inspection records are reviewed

Every payment must be linked to something that the buyer can see, not a date on the calendar that could be or could not be related to accomplishing work.

Quality Standards and T1 Sample Approval

The terms of the agreement should be specific and measurable, such as what important dimensions are, what tolerances are, and what sampling level (such as an AQL standard) should be used when inspecting.

First-article approval, often referred to as T1, should be a defined gate: the mold should not go into production until the sample parts have been measured against the drawing and formally accepted. Also required documentation should be outlined: dimensional measurement reports, material certificates, photos, or video of the trial so overseas purchasers who will not be able to attend in person will have something to refer to. The agreement should also ensure that the buyer has the option to employ a third-party inspector rather than just the factory’s inspector.
For more on sampling levels and inspection standards generally, see our guide to quality control in injection molding.

Mold Life, Maintenance and Repair Responsibility

A mold designed in H13 hardened steel will differ substantially in its lifetime from a mold designed in a softer, faster tool steel, and the agreement needs to be sensitive to this by expressing an expected number of shots for the steel grade specified. It should also make it clear who pays for wear components: routine replacement is normally the buyer’s cost as a normal part of production, while premature failure caused by a mold defect is not.

A preventive maintenance schedule based on cycle counts, not left informal, is the best way to keep a tool from silently degrading until a batch fails.

Lead Times and Delivery Terms

Tooling lead time and production lead time are two numbers—it is important to identify them and state them separately: how many days from kickoff to T1 sample and, once the mold is approved, how many days from PO to shipment for a production run.

The cost and risks associated with each Incoterm should be clearly defined in EXW, FOB a named Chinese port, CIF, or DDP, as it affects the cost and risk of the transaction at a different stage, which is important and would not necessarily be understood by a buyer with little knowledge of export logistics. The agreement should also clarify the responsibilities for obtaining the export documentation and who the exporter of record is.

Engineering Changes After the Steel Is Cut

Even after a mold is made, the designs are changed. The agreement should specify how the request for a change is made after steel has been cut, including how the cost of the change is quoted before the start of work and how it may impact an existing mold life warranty agreement.

Law, Language and Dispute Resolution

With a China-based supplier, Chinese law with a Chinese court or arbitration body as the forum is usually the more enforceable choice. However, this seems counterintuitive to a foreign buyer. It is hard or impossible to enforce a judgment against a factory that has no assets in your home country.

Where the agreement exists in both English and Chinese, you should be aware that a Chinese court or arbitration body will use the Chinese language version of the agreement as the basis for deciding the case. Both should be carefully and consistently drafted, not translated one after the other after both have been completed, or else a discrepancy between the two versions will give the advantage to the factory in the case of a dispute.

CIETAC (China International Economic and Trade Arbitration Commission) is the most commonly cited arbitration body in well-structured China manufacturing contracts. Alternative international arbitration proceedings are available but are typically more time-consuming and significantly more costly.

It’s also important to verify the China supplier’s registered business scope through China’s GSXT system to check if they are actually a business and if they can do manufacturing or mold making before signing anything. When you are interested in a supplier that claims to be a factory but in fact is a trading company that holds no contract with the manufacturer that makes your parts, it is a serious issue if you ever need to enforce a mold ownership clause against whoever actually holds your tool.

Red Flags Worth Walking Away From

A few of these are best treated as deal breakers rather than points to negotiate:

• A factory that will not enter into a written agreement regarding ownership of molds.
• Failure to physically name the mold with your company name and mold ID.
• Ambiguity on the question of whether a quote is for a full mold or shared base inserts
• Failure to agree on a specific mold removal schedule.

None of these is, in and of itself, enough to prove bad faith, but combined, they paint a picture of a factory setting out to maintain control over the relationship rather than be a clear partner.

Questions to Ask Before You Sign

• When I pay for the mold in full, can I get it in my hands if I want it, and how many days will it take?
• Is this a complete self-contained mold or cavity inserts on a base that you keep?
• What sort of documentation will I get at T1 approval before final payment for tooling?
• Is my design covered by an NNN agreement, separate from the manufacturing agreement itself?
• What will happen to my tooling if we don’t continue to place production orders?

FAQs

Does the Chinese mold I paid for necessarily mean that I own it?
No, if there is no express ownership clause that specifies the mold by number, then who has the mold and who controls it would usually be based on who has the physical possession of the mold, which would be the factory. A written agreement establishes the buyer’s ownership.

What is the difference between an NDA and an NNN agreement?
The typical NDA covers disclosure of confidential information to the public. In the more typical China sourcing scenario, an NNN agreement provides legal protection against a factory taking your design and using it for its own purpose or bypassing you to enter into direct sourcing contracts with customers or suppliers.

If my tooling price for a part is lower than all the other guys’, what does that say?
Be sure to verify what is being provided. A much lower quote often means you’re only paying for cavity inserts on a shared base that the factory keeps, rather than a full mold that you can move anywhere you want.

If I ask for the mold, how long will it take?
There is no standard, but agreements typically include about thirty (30) days from the written request or, in case of failure to meet such request, a liquidated damages clause. If there is no timeline in writing, recovery may be indefinitely postponed.

Would CIETAC and a country’s judiciary be the forum for resolving conflict?
From a Chinese manufacturer’s perspective, CIETAC arbitration or a Chinese court will be more enforceable than a foreign judgment, as the factory will have its assets in China. This is a decision to be taken with legal guidance well versed in cross-border manufacturing.

Final Thoughts

If a supplier is willing to write them down clearly and without resistance, it’s a good sign of how the rest of the relationship will develop. Requests for explicit ownership of the mold, physical marking, explicit T1 documentation, and a real retrieval timeline are not uncommon. They are the baseline any transparent manufacturer should be comfortable agreeing to before a project starts.

If you’re considering a supplier, request a sample tooling agreement before signing a project. If a factory has nothing to hide, it will have one ready.

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