How to Select an Injection Mould for Consistent Tight Tolerances

Maintaining tight dimensions across multiple production runs starts with choosing a mould suited to the part, materials, and planned output. Evaluate the mould steel, base material, cavity arrangement, surface finish, and runner system together. Before production release, require trial runs, dimensional checks, and approval of representative samples. Also establish how the supplier will support maintenance and any production issues over the mould’s service life.

Selection Priorities

• Define the component’s drawing requirements and forecast volume before deciding on the mould base, steel, or number of cavities.
• Review the available material choices: S50C, P20, or 1.2738 for the mould base, and H13 or 718H for the mould steel. The stated mould life spans 50,000 to 1,000,000 shots; confirm a suitable target for the project.
• Include dimensional inspection, mould trials, and sample sign-off in the approval plan. For recurring orders, agree in advance on measurement criteria and sample-approval procedures.
• Check the supplier’s experience against the intended application. Longterm identifies consumer electronics and automotive components among its injection-mould application areas.

How Configuration Affects Repeatability

Consistent dimensions depend on a mould design that fits the component and production plan, followed by verification using trial parts. Available configurations include single- and multi-cavity layouts, SPI or VDI surface finishes, and an optional hot runner. Since no universal tolerance figure is provided, share the part drawing and required tolerances with the supplier and have project-specific inspection limits documented.

Longterm’s custom precision plastic injection mould specification lists S50C, P20, and 1.2738 as mould-base materials, with H13 and 718H available for mould steel. The stated service-life range is 50,000–1,000,000 shots. The listed MOQ is one set and the delivery estimate is 20–35 days. Quality procedures include incoming inspection, mould trial testing, dimensional inspection, and a full inspection before shipment.

For repeat orders, ask for recorded dimensional results and make sample approval a defined release step. Longterm reports ISO 9001:2015 certification for the design, manufacture, and sale of precision moulds, as well as the sale of plastic products. Reported customer projects include a double-shot overmoulding tool for a French customer, with positive feedback on alignment and trial-sample stability, and an appliance mould for a US customer whose samples met the specified requirements.

Options to Confirm with Your Supplier

Frequently Asked Questions

What service life is stated for the custom precision injection mould?

The listed range is 50,000–1,000,000 shots. Discuss the applicable target with the supplier based on the mould design and your production needs.

Which checks are performed before delivery?

The stated process includes IQC incoming inspection, mould trial testing, dimensional inspection, and a full pre-shipment inspection. Identify the dimensions and samples that need documented approval for your project.

Can the mould design accommodate different part requirements?

Options include single- or multi-cavity construction, SPI or VDI finishes, and an optional hot runner. Provide a part drawing or sample to review the suitable configuration.

Recommendations for Repeat Production

Before placing a mould order, document the part tolerances and production forecast, then agree on materials, cavity layout, and finish. Make trial testing, dimensional reporting, and sample approval explicit conditions for production release. Longterm lists an MOQ of one set, delivery in 20–35 days, and ongoing maintenance guidance, spare parts, and online technical support. For project-specific technical discussions, contact rogerluo@longterm-mold.com.

About Longterm

Longterm Manufacturing Solutions Limited was established in 2010 and serves customers in the US, Europe, Australia, and other international markets. Its services include mould design, tooling, precision machining, mould manufacturing, and parts production. The company reports a 2,000-square-metre factory and an R&D team of five engineers focused on moulds and precision machining. It holds ISO 9001:2015 certification and has worked with customers across several industries.