While injection molding is more commonly associated with production of mass reproducible parts at high volume. Injection molding is also important in low volume production. This is the case in for example development of prototypes, pilot scale production runs, high precision engineering parts for medical, automotive or aerospace applications, custom parts and components or limited edition products. You may require a single part or a few hundred parts. Anything under a thousand parts can generally be regarded as low volume injection molding. This article discusses low volume injection molding and we explore some companies specializing in this across the world.
Lead Times for Low Volume Injection Molding
You might be quick to think that low volume equals shorter lead times. This is not necessarily the case. Injection molding at its core, is aimed at producing as many parts within a given time as possible. It is primarily directed at mass production. This is partly achieved through producing multiple parts per cycle and employing the latest process control and optimization technologies to ensure the process runs as smoothly as possible from cycle to cycle without any hitches. This way yield is optimized. Now when running low volume productions, process control and optimization is not compromised, the system runs as it should, however it could mean producing less per cycle or it could mean running fewer cycles. Therefore the lead time may not directly correlate to the number of parts you are ordering if the manufacturer is running a multicavity system. For larger products or complex small parts that are made using single cavity molds, the lead time can be significantly reduced by reduced production time since in this case the order quantity is directly adding to the lead time.
Other factors that affect lead times also come into play in lead times like sourcing raw materials, setting up the machine for the production run, quality checks, testing and shipment. Some of these processes are independent of the quantity of the order. Such that in some cases low volume orders may take just as long as high volume orders especially if from the same location. This applies in particular if the manufacturer is operating a just in time system.
Cost of Low Volume Injection Molding
While the cost of any injection molding service varies significantly from company to company, understanding the costs involved in low volume injection molding might help you understand what you are getting quoted by a company.
The injection molding machine from the feed to the gate entry point is not product specific and remains constant regardless of the shape of the product being molded. The part that is product dependent is the mold. For a unique part such as a prototype, a mold needs to be made specifically for the product and cannot be reused for another customer. One may choose to use aluminium mold which could significantly lower the cost of material as opposed to steel molds. Bear in mind that the aluminium molds are less durable compared.
You might find in some cases that it costs just as much to make 10,000 pieces as it does to make a thousand pieces. This is the brilliant economics of the scale injection molding process offered to large scale manufacturers. While low volume injection molding may not take advantage of this economics of scale, the precision and low tolerance and other advantages of injection molding still remains.
The mold is a significant chunk of the cost of injection molding and it is a very crucial part. You might choose to have your mold designed and fabricated by another dedicated mold maker. This gives you ownership of the design and physical mold. In such cases, the injection molding company only charges you for the production and related services.
Injection Molding Companies Specialized in Low Volume Production
If your aim is to produce a few pieces or less that a thousand pieces, you might be better off going to a company that is primarily focused on customers who want just that. This is not only because of cost, it is also to do with the quality of service to expect. Companies focused on low volume tend to understand the specific needs of such customers and have tailored their services as well as their production process to small volume injection molding requirements.
Whereas going to a company who’s primarily focused on large volume production, yes they might accept your order, but know that they would most likely be sorted or fitting you in. While there are technologies and automated systems that allow faster change overs of molds to allow fast and seamless changeover from one product type to another, In most cases changing molds can take hours and the companies are less willing to do this to make a few parts and then have to lose some time to switch back. Companies dedicated to low volume production have already made the capital investment in systems that allow quick change over or at least have aligned their operations to allow for the frequent switch to meet diverse customer needs.
Protolabs
With headquarters in Minnesota in the United States, protolabs also has facilities in other countries such as a 3D printing facility in the UK. Protolabs has a focus on injection molding parts for the medical and aerospace industry. They mostly work with aluminium molds.
Elite Mold and Engineering
They offer injection molding services for clamp forces between 55 and 390 tons with aluminium or soft steel molds. They offer both bridge tooling for production parts as well as lifetime low volume production. Although the company also offers high volume injection molding services, it does have a dedicated low volume injection molding operation.
LS Manufacturing
Based in China, they provide rapid prototyping injection molding services with maximum part size of 12000 x 1000 x 500 mm and a mold cavity tolerance of +/- 0.05mm.. Their services meet ISO 9001:2015 certification standards. While for low volume they produce between 1 and 10,000 units, they also cater to high volume injection molding over 1 million units. They state a standard lead time of 2 to 3 weeks. They focus on precision parts to serve the automotive, medical devices, consumer electronic, aerospace, industrial equipment, robotic automation, education and renewable energy industries.
Midwest Mold
Founded in 1994. Midwest Mold is located in Roseville Michigan in the United States. The company’s low volume injection molding service makes use of 100, 156 and 330 ton inhouse plastic injection molding machines. They mainly make use of aluminum molds for low volume injection molding. For low volume injection molding services are typically less than 10,000 parts annually.
Low Volume Injection Molding for Mold Testing
Whether you are seeking low volume or high volume injection molding. The mold is a key asset in manufacturing plastic parts. Often the mold is manufactured by a company that specializes in mold making while the injection molding process is either done in house or contracted to an injection molding company. In either case a key step is testing the mold to ensure it meets all specifications and the parts are coming out as designed. Cavity Mold is a dedicated Mold Maker that also offers mold testing as part of its service offerings. The company produces high quality molds with high precision with over 15 PC controlled horizontal injection molding machines with clamping pressure ranging between 50 and 300 tons. The services offered include standard as well as advanced injection molding such as insert molding, over molding and hot runner systems.
Conclusion
Low volume injection molding is often required for prototype development, precision parts in high end applications like medical devices, aerospace and automotives, mold testing or making small quantities for limited edition or market testing. There are a number of companies across the world who specialize in low volume injection molding. Most companies make use of aluminium molds for small volume as this offers significant cost savings without compromising on quality. Parts requiring high precision like those of medical device components, automotives and aerospace, are more commonly manufactured using low volume injection molding.
By Ololade Olatunji
May 6, 2026