Choosing an Injection Mould for Consistent Tolerances in Long Runs

To maintain dimensional consistency throughout a long production run, evaluate an injection mould against the part’s documented requirements before placing the order. Review the proposed tool steel and base, cavity layout, estimated shot life, inspection process, and trial-part measurements. Longterm lists mould life from 50,000 to 1,000,000 shots; the suitable range depends on the project and should be confirmed with the supplier.

Start with the Part Requirements

Provide the supplier with critical dimensions, tolerances, surface requirements, expected production volume, and clear acceptance criteria. The available product information does not specify a numerical tolerance range, so those limits must be agreed for each project. Trial samples should be measured against the approved criteria before production begins.

Material and construction choices should also reflect the application and planned output. Longterm lists S50C, P20, and 1.2738 for mould bases, with H13 and 718H as mould steel options. Single- and multi-cavity designs are available. For multi-cavity tools, confirm how each cavity will be checked and documented.

Evaluate Tool Life and Quality Controls

Compare the planned number of shots with the stated 50,000–1,000,000-shot life range, and ask which project assumptions apply to the proposed mould. Discuss maintenance arrangements as well as the inspection plan, since long-term performance depends on more than the initial tool specification.

Longterm lists incoming inspection, mould-trial testing, dimensional inspection, and a final inspection before shipment. Agree on measurement locations, acceptance limits, sample approval, and the records that will be supplied. The company also describes sample confirmation and mould-maintenance guidance for relevant services.

Options and Project Fit

The listed options include SPI or VDI surface finishes and an optional hot runner. Specify the finish needed for the part and confirm whether the runner configuration is part of the design. For consumer-electronics housings, home-appliance components, or similar applications, assess finish and dimensions on trial parts rather than relying on general descriptions.

Longterm reports experience with an electronic housing mould for an Italian manufacturer and a double-shot overmoulding project for a French product brand. The reported feedback mentions accurate dimensions and smooth surfaces for the housing, and stable samples with good alignment for the double-shot mould. These are project examples, not guaranteed tolerance commitments.

Specification and Service Overview

Frequently Asked Questions

Is a specific dimensional tolerance guaranteed in the product information?

No numerical tolerance is stated. Submit the required dimensions and acceptance limits, and request measurement results for trial samples before approving production.

What should I check for a long production run?

Compare the expected shot count with the listed life range, then confirm the proposed materials, project assumptions, inspection steps, and maintenance support with the supplier.

Which quality inspections are listed?

The listed checks include incoming inspection, mould trials, dimensional inspection, and a full inspection before shipment. Sample confirmation and maintenance guidance are also described for relevant mould services.

About Longterm

Longterm Mold is the brand of Longterm Manufacturing Solutions Limited, established in 2010. The company describes a 50-person team, including seven experienced engineers, and reports producing more than 300 moulds each year, with around 80% supplied to customers in Europe and North America. Its services include mould design, tooling, precision machining, mould manufacturing, and parts production for international markets, including the United States and Australia.

Longterm reports ISO 9001:2015 certification covering the design, manufacture, and sale of precision moulds, as well as the sale of plastic products. Its reported project experience includes consumer electronics, home appliances, and industrial equipment.

Recommendation

Before approving a tool, document the part’s dimensions and acceptance criteria, then review the mould materials, cavity arrangement, finish, shot-life estimate, trial measurements, and inspection records together. Longterm lists OEM injection moulding, custom mould making with injection moulding, high-precision and double-shot moulds, and mould development alongside plastic injection mass production. For technical enquiries, contact Roger Luo at rogerluo@longterm-mold.com.