Buying an injection mould from China: ownership, steel, trials and transfer

This guide covers plastic injection moulds (molds, in US spelling) commissioned from a mould maker in China, whether the parts are moulded there or the mould travels to another moulder. Sinospect checked the standards, the law and the figures below at their sources on 26 September 2026.

What the buyer owns: the mould, the files and the design

A mould order buys three things that can be separated: the steel mould, the design files behind it, and the rights in the part design. A factory can hand over the mould and keep the files. Harris Sliwoski, a law firm that works on manufacturing contracts in China, advises covering each one in the agreement and settling ownership before the steel is cut.

What Chinese law says about a mould

A mould made to order falls under the contract for work (承揽合同) in the Chinese Civil Code. These articles decide who holds it and on what terms:

For a buyer, two consequences follow. A mould maker that is owed money, even on another order, can hold the mould. The contract can take that right away, since Articles 449 and 783 give effect to what the parties agreed. The translations are Sinospect’s, from the Chinese text of the Civil Code, which prevails; a lawyer qualified in China should review the agreement itself.

The tooling agreement

The company that physically holds the mould signs the agreement, before any tooling payment. Drawing on the Civil Code and on published practitioner guidance, the agreement states:

• the buyer’s ownership of the mould, the design files and the part design once the tooling price is paid;
• that the mould stays free of any lien or retention, whatever the debt (Articles 449 and 783);
• written consent before any mould shop takes on the main work, and the name of that shop (Article 772);
• confidentiality, with copies of the mould and its files only by permission (Article 785);
• a nameplate with the buyer’s name and an asset number, and a register with photographs;
• use of the mould for the buyer’s parts only;
• storage, maintenance and insurance, and how long an idle mould is kept;
• release within a set number of days, with the handover pack;
• damages for late release or unauthorised use, and a dispute route that works against the Chinese company.

Practitioners report what skipping it costs. Harris Sliwoski cites a buyer who paid $200,000 to recover moulds bought for $80,000 eight months earlier. QualityInspection.org reports suppliers asking 15 to 30% on top of the tooling price before releasing a mould, and recommends a Chinese-language agreement drafted by a China lawyer. FBM Sourcing reports that factories typically store a buyer’s tooling for one to two years after the last run unless a longer period is agreed, and that some scrap moulds after a storage period unknown to the buyer.

Specifying the mould: class, steel, tolerances and finish

Class. The SPI classes (SPI is now the Plastics Industry Association) grade a mould by expected life:

Naming the class in the order gives the steel, the components and the cycle count something to be checked against.

Steel. Quotations name steel by grade or trade name: P20 (1.2311), 718 (1.2738, a pre-hardened P20 type), stainless 420-type steels (1.2083) sold as S136 or Stavax ESR, H13 (1.2344), or NAK80. The trade names come from the steelmakers. Uddeholm’s Impax Supreme is a 1.2738 steel supplied at 290–330 HB, sold in East and South-East Asia as AS 718 Supreme. Its Stavax ESR is a stainless AISI 420 modified steel hardened to 45–52 HRC for injection moulds. Daido’s NAK80 is supplied pre-hardened to 40 HRC for mirror finishes. The name in a quotation is where the check starts; the evidence is the mill certificate traced to the blocks used, the steelmaker named on it, and a hardness reading taken on the finished mould. Article 774 gives the buyer the right to inspect the materials the mould maker supplies.

Tolerances. Both tolerance standards for moulded plastic parts changed in 2026. ISO published ISO 20457:2026 in August and withdrew the 2018 edition. In China, GB/T 47067-2026, a modified adoption of ISO 20457:2018, has applied since 1 August 2026, and GB/T 14486-2008 is withdrawn. The drawing names the standard and its edition; a quotation citing GB/T 14486 cites a withdrawn standard. ISO’s abstract of the 2018 edition places surface imperfections such as sink marks, flow structures, roughness and joint lines outside its scope, so cosmetic criteria are written separately.

Finish. The SPI finish grades run from A-1 to D-3: A grades are diamond-buffed high gloss, B grades are sanded with 600, 400 or 320 grit paper, C grades are stoned matte, and D grades are dry-blasted textures. Spark-eroded textures are specified on the VDI 3400 scale, from the German engineers’ association guideline of June 1975. The drawing gives one grade per surface.

From design review to approved sample: the gates

Each gate produces a record, and each payment follows a record.

• Design review (DFM). Wall thickness, draft angles, gate position, undercuts, parting line and shrinkage, often with a filling simulation (Autodesk Moldflow or Moldex3D) that predicts sink marks, weld lines and air traps. Approved before the steel is cut.
• T1 and corrections. The first parts from the finished mould come with a dimensional report, and small defects are normal at this stage. The mould is corrected and sampled again (T2, T3) until a sample is approved; the signed sample and its dimensional report become the reference for production.
• Release inspection. Steel and hardness records, cooling circuits numbered and tested, spare parts against their list, water lines drained or preserved, the data pack complete and the acceptance report signed.

Mould makers publish payment splits such as 40% with the order, 30% at T1 samples and 30% before shipment or after approval; 30%, 30% and 40%; or half with the order and half after sample approval. Whatever the split, the last payment follows the signed acceptance report and the handover of the files.

Where moulds are made

Huangyan, in Taizhou (Zhejiang), is known as China’s home of moulds (中国模具之乡). Zhejiang Daily reported in May 2025 an annual mould output close to CNY 30 billion, 132 mould companies above the statistical size threshold, and national market shares of 80% for extrusion moulds, 75% for blow moulds and 30% for injection moulds. Ningbo has its own specialisms: large plastic moulds in Ninghai, precision plastic moulds in Yuyao, die-casting moulds in Beilun and household-appliance moulds in Cixi. In Guangdong, plastic and metal-stamping moulds make up over 70% of Shenzhen’s mould output. Sinospect’s Ningbo office is within reach of both Zhejiang clusters.

Moving a mould out of China

A mould that travels is declared under HS subheading 8480.71, moulds for rubber or plastics of the injection or compression type. Wooden crates follow ISPM 15, the international standard for treated and marked wood packaging. The handover pack travels with the mould: 2D and 3D design files, steel certificates and hardness records, hot-runner documentation, the cooling layout, spare parts and their list, the final dimensional report, approved samples and the process settings from the final trial. At the new moulder, the mould runs its own first trial, measured against the drawing and the approved samples. The release deadline in the tooling agreement sets the timing.

Moulds for medical parts

For medical parts, the moulder’s quality system and cleanroom count as much as the mould. ISO 13485:2016 remains the quality management standard for medical devices (confirmed in 2025), and ISO 14644-1:2015 classifies cleanroom air cleanliness. The guides to sterile medical disposables from China and to verifying a Chinese medical device manufacturer cover the product side.

Buyer checklist

Before the first tooling payment

• A tooling agreement signed by the company that holds the mould: ownership, files, retention excluded, subcontracting only with consent, copies only by permission, storage period, release deadline, enforcement in China.
• The mould maker’s business licence, and the company that will hold the mould identified.
• The class, cavity count, target cycle time and expected life in the order.

Before the steel is cut

• The DFM report and any filling simulation approved.
• Steel grade and steelmaker named, with a mill certificate for the blocks.
• The tolerance standard and edition on the drawing (ISO 20457:2026 or GB/T 47067-2026), written cosmetic criteria, and one finish grade per surface.

Before release and the last payment

• T1 report, corrections closed, approved sample signed.
• Release inspection: hardness reading, cooling test, spare parts, data pack, signed acceptance report.
• Nameplate and asset number fitted; register updated with photographs.
• For a mould that travels: HS 8480.71, an ISPM 15 crate, rust protection and the handover pack.

Frequently asked questions

Sources

Checked at the sources on 26 September 2026.

• Standards: ISO 20457:2026, ISO 20457:2018 (withdrawn), GB/T 47067-2026 and GB/T 14486-2008 (China’s national standards portal), VDI 3400, ISO 13485:2016, ISO 14644-1:2015
• Law and trade: Civil Code of the People’s Republic of China (Chinese text), US Harmonized Tariff Schedule, heading 8480, ISPM 15
• Steelmakers: Uddeholm Impax Supreme, Uddeholm Stavax ESR datasheet, ASSAB plastic moulding steels, Daido plastic mould steels
• Classes and finishes: SPI mould classes (Montrose Molders), SPI finish grades (Fictiv)
• Practitioners: Harris Sliwoski, guide to molds and tooling, Harris Sliwoski, who owns your molds, QualityInspection.org, FBM Sourcing
• Clusters: Zhejiang Daily, 16 May 2025, MM Metalworking (China mould clusters)