PR-02 · Process hubs
Injection molding is how most plastic parts are mass-produced. Melted plastic is forced into a steel mold shaped like your part, cools in seconds, and pops out, over and over. The mold is expensive and takes weeks to make, but after that each part costs very little. It makes sense once your design is final and you need thousands of parts. Read our guide on getting a mold made before you start.
Foreign-owned, foreign-managed factory (Sofeast group) with English-speaking staff in every department
Dongguan · Chang'anDMG 5-axis and rows of 3-axis CNC in a 5,000 m² Chang'an base
Dongguan · Chang'anProprietary zinc multi-slide die casting, invented in 1936
Dongguan · DalangMulti-cavity pen molds and two-shot keycap molds
Dongguan · Chang'anSilver contacts and electrical contact assemblies, riveted or welded in the mold
Dongguan · FenggangSino-British founders (CEO Vader Yu and James Murphy) and English-speaking project managers
Shenzhen · Bao'anCustom screws and fasteners at scale: 120 screw machines, about 1.2 million pieces a day
Shenzhen · LonghuaAutomotive white-body stamping prototypes and full-size show-car models
Shenzhen · Bao'anNew-energy prototypes: battery packs, charger housings, inverters, cooling modules
Shenzhen · GuangmingGet 3 quotes
Describe the part once. We send it to up to 3 shops that fit, and they quote you directly.
21 guides
Everything we've written about Injection molding, starting with the basics.
Start hereHow injection molding works, why it makes plastic parts so cheap at volume, what the catch is, and when your product is ready for it.
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01Choosing · 7 minThe difference between aluminum "rapid" tooling and hardened steel production molds, with cost, speed and lifetime compared in plain English, and how to choose for your first run.
02Working in China · 18 minA plain-English walkthrough for first-timers. What an injection mold is, when you need one, what it costs, how long it takes, and how to make sure the mold belongs to you.
03Cost · 9 minThe two costs of injection molding (the mold and each part) explained for first-timers, with a simple way to work out when molding becomes cheaper than prototyping methods.
04Design · 10 minThe handful of design rules that make plastic parts moldable and cheap. Draft, wall thickness, ribs, bosses and undercuts, explained simply with the reason behind each.
05Basics · 6 minHow products get soft-touch grips, rubber seals and molded-in metal parts. Overmolding, two-shot molding and insert molding explained simply.
06Basics · 10 minHow custom silicone parts like keypads, buttons, gaskets and seals are made, what hardness and key feel mean, compression molding vs LSR, and how to order them in Shenzhen and Dongguan.
07Design · 9 minWhat design for manufacturing (DFM) means, why it decides most of your product's cost, the core rules, when to do a DFM review, and how DFM feedback from Shenzhen suppliers works.
08Design · 7 minWhat "±0.05 mm" means, why tighter tolerances cost more, and how to decide which features of your part actually need them.
09Design · 9 minWhat design freeze means, why late changes are so expensive in hardware, and how engineering change requests, orders and notices (ECR, ECO, ECN) keep you and your factory on the same version.
10Basics · 12 minThe three test builds between a working prototype and mass production, explained for first-time founders. What each build is for, roughly how many units you make, and what usually goes wrong.
11Cost · 8 minYou need around 50 plastic parts. Should you 3D print them, vacuum cast them, or make a mold? A plain-English comparison of cost, speed, looks and material, with a simple way to compare quotes.
12Cost · 10 minThe cost buckets of developing and manufacturing a hardware product, explained for first-timers. Design, prototypes, tooling, certification and the first production order, with typical ranges where they're widely published, plus the costs people forget.
13Basics · 9 minA realistic timeline for bringing a hardware product to market, stage by stage, for first-time founders. Where the time actually goes, what slows projects down in Shenzhen, and how to save weeks.
14Working in China · 10 minA step-by-step, neutral guide for first-time hardware teams. How to find suppliers, tell factories from trading companies, check what you can, compare quotes, and start small.
15Design · 8 minHow to tell a factory exactly what colour, gloss and texture you want, using colour codes, physical samples, texture standards and a simple written spec. For first-time hardware teams.
16Choosing · 8 minWhat a request for quotation (RFQ) is, what to put in it, and how to write one that gets clear, comparable quotes from Shenzhen suppliers. With a checklist you can copy.
17Working in China · 8 minWhat an NNN agreement is, how it differs from a standard NDA, why it's commonly recommended when working with Chinese manufacturers, and what it can and can't do. Plain-English background, not legal advice.
18Basics · 11 minThe stages of making a physical product, from first sketch to boxes on a ship, explained for first-timers. What happens at each stage, why it matters, what you get out of it, and who in Shenzhen helps.
19Basics · 10 minWhy a product that works as 10 prototypes can fail at 1,000 units, what changes in parts, people, testing, documents and cash as you scale, and the steps between a working prototype and your first production run in Shenzhen.
20Working in China · 10 minWhat pre-shipment inspection is, when to inspect, how AQL sampling works in plain words, what an inspector checks, and how to prepare so the report is actually useful. For first-time importers.
You should. Put mold ownership (私模) and the transfer terms in the contract.
The first parts from the new tool, used to find defects before modifications.