Injection molding is among the most popular manufacturing processes in the world. From consumer electronics to auto components and medical devices, the technique is used in several different products. Yet, the most frequent query that every business asks itself is: How much does injection molding cost?
The answer to this question is not so simple. Injection molding expenses vary depending on several factors, including mold design, the material used, part complexity, the number of parts made, and completion needs. Like many processes, tooling materializes at a huge expense for investment in injection molding, unlike 3D printing. However, after tooling has been developed, the cost per part will decrease significantly with increasing production volumes.
This article discusses injection molding costs in depth – breaking down tooling, material, and production costs, giving real-life ranges of costs, and discussing ways to cut costs. At the end of this article, you will understand not only the cost of injection molding but also why it is so expensive and what you can do to get the most out of your money.
What Constitutes the Cost of Injection Molding?
Injection molding costs can be broken into two general categories: fixed manufacturing costs and variable manufacturing costs.
Fixed cost: Mainly die molding tooling. These are expenses that are burdened on the front end and do not vary with the number of parts.
Variable costs: Material, machine time, as well as labour, finishing, and packaging costs, which are proportional to the amount of production.
The cost of injection molding tooling
The mold is the biggest cost of injection molding. Tooling costs range greatly based on size, complexity, and material.
Simple aluminum molds: $2,000 – $5,000
Moderately complicated steel molds: $10,000 – $50,000
Large, complex or multi-cavity molds: $500,000+ – $1 million + (Pelton and Murphy, 1989)
Factors Affecting Mold Cost
- Cavities – Single cavity molds are less expensive but have fewer parts per cycle. Multi-cavity molds are more expensive, but more efficient.
- Aluminum molds: they are cheaper, and they take less time to produce, but have a short life. Steel molds are long-lasting but costly.
- Complexity – Factors such as threads, undercuts, and side actions increase costs.
- Size – The larger the molds, the more material and time it takes for the mold machining process.
- Tolerances and Finish – High-precision and mirror finish particle molds require additional machining as well as polishing time.
Mold costs are the biggest promoter of low-volume or startup projects, but in the case of mass production, mold costs are very economical.
Material Costs in Injection Molding
The raw material of the plastic has a huge impact on the cost per part. Parts are priced by the kg/pound of material, and part consumption is dependent on part weight.
- Commodity plastics (PP, PE, ABS, PS): $1 – $3/Kg
- Engineering plastics (Nylon, PC, PBT, Acetal): 3 – 10 /kg
- High performance plastics (PEEK, PSU, LCP): $20 – 100+ per kg
Other considerations:
- Colorants – Custom colors will increase the price.
- Filler – Strength is increased, but price is raised by the use of glass fiber or mineral reinforcement.
- Content utilizing recycled materials – Lower in cost, but could affect quality.
A small part made of ABS could cost only a few cents for material, whereas a large part made of PEEK could cost tens of dollars.
Machine Time and Cycle Costs
Injection molding machines are charged at hourly rates, some of which can be as low as $25/hour for small machines or as large as $150/hour for large and customized.
The amount of time the molding machine takes to fill a mold, cool it down, and eject a part is known as cycle time; the number of pieces produced in an hour is determined by the cycle time.
Example:
Segment with 30-second cycle time on a machine costing $60/hour = $0.50 per cycle (material not included).
However, a part using a 10-second cycle = $0.17 per cycle, which is much cheaper.
Cycle time is influenced by:
- Part size and wall thickness.
- Material cooling rate.
- Procedure to design the mold and cooling channels
Maximizing cycle time is one of the largest cost-saving options.
Labor Costs
While injection moulding is very automated, it still requires labour for the following:
- Programming and preparation of machines.
- Quality inspection.
- Secondary processes (cutting, assemblage, and packaging).
Labor rates vary by region. Wages in the U.S. range from $20 – $40 per hour, whereas in Asia, they can be much lower.
Secondary Operations Finishing
Not all molded parts are ready for use when they are taken from the press. Carrying out the above activities is commonly followed up with:
- Trimming excess material.
- Painting, coating, or plating.
- Touchscreen marking, pad marking, and laser marking.
It involves building up a multitude of things.
Depending on its complexity, overhead costing can cost as little as a few cents to several dollars per piece.
Packing and Cost of Shipping
Global supply chains depend a lot on logistics. Shipping for sensitive or medical-grade parts requires adherence to high standards that raise expenses. Hardwood can also cost thousands of dollars to get shipped abroad and molds added.
Typical Cost Examples
Let’s consider some approximate real-world cost situations:
No elaborate consumer product (phone case, ABS).
Mold: $5,000 (aluminum, single-cavity)
Per-part cost: $0.50 – $1.00 at 10,000 units
Total cost: ~$10,000 – $15,000
Dashboard clip in Automotive (nylon + GF)
Mold: $30,000 (steel, multi-cavity)
Per-part cost: $0.20 – $0.40 at 500,000 units
Total cost: ~$130,000 – $200,000
Medical device (polycarbonate) (high precision) housing
Mold: $100,000+ (steel, tight Tolerances, multi-cavity)
Per-part cost: $2 – $5
Total cost: Millions throughout the product lifetime
The following illustrates economies of scale in expenditures.
The influence of the scale of production on cost
The biggest cost element is the number of parts that you intend to make.
- Low-volume (1 to 1000 units) – Part-level cost is very high due to the amortization of the mold. More affordable alternative prototyping methods may be used, such as 3D printing or urethane casting.
- Medium volume (1,000 to 50,000 units) – Aluminum molds are cost-effective for high-volume injection molding at a rapid turning rate.
- Injection molding is the cheapest per part production because in injection molding, we can make huge quantities of parts (50,000- millions) with steel molds.
As a rule of thumb, the larger the volume, the lower the cost per piece.
Rapid vs. Traditional Injection Molding Cost.
Rapid injection molding uses aluminum molds because of faster delivery and lower initial costs.
Rapid molds: $2,000 – $15,000, lifespan 5,000 – 50,000 shots.
Production steel molds: $50,000 – $200,000+, life: 500,000 – 1,000,000+ shots.
Steel molds are preferable for a long-run, high-volume application, whereas rapid injection molding is ideal for prototyping, bridging, market testing, or similar.
Global Cost Differences
The location of your manufacturing has dramatic cost implications:
United States/Europe – Due to labour rates, tooling costs are higher ($20,000-$100,000)
China/Asia – Lower tooling costs ($5,000 – $20,000) with changing quality.
Hybrid approach – Many companies plan molds in the West, make them in Asia, and carry out production at the locale.
Offshore production will yield cost savings at a price, though some may pay a premium in lead times, IP securing, and communication.
Hidden Costs to Consider
Besides apparent costs, there are hidden costs:
- Tooling – Altering the mold die once production has begun is quite expensive.
- Downtime – Downtime is typically caused by machines breaking down or molds that require repair and maintenance, running behind schedule.
- Scrap rate – Waste of materials in runners, etc. Defective parts.
- Regulatory compliance – Certifications and tests for medical/aerospace parts result in added cost.
Strategies to Reduce Injection Molding Costs
- Design for Manufacturability (DFM) – Simplify Geometry, Avoid Undercuts, & Uniform Walls
- Reduce material consumption – Make use of low-cost resins, filler/fly ash, and recycled material.
- Integrate parts – Save on assuring parts by designing multifunctional parts.
- Use of family molds – Multiple parts in one mold allows it to save tooling costs.
- Design production volume appropriately – Match mold grade with lifetime usage.
- Negotiate with Suppliers – Long-term contracts drive down Per Part Pricing.
- Nearshoring – Making the best balance between logistics and costs through local sourcing.
Injection Molding vs. Other Processes: Perspective of Cost
- 3D Printing (Additive Manufacturing) – Lower Cost of Prototype and Very Low Volume Injection molding is cost-effective after ~1,000 units
- CNC Machining – ideal for small orders, and for metals, but costly for plastics if manufacturing in large quantities.
- Urethane Casting – Low tooling cost, but the cost per part is higher, and it is limited to a range of materials
Injection molding is unsurpassed in terms of scalability and low cost at mass volume.
Conclusion
So what is the cost of the injection molding? This really varies with part complexity, material, tooling, and production volume. Tooling can vary from several thousand dollars for simple molds to hundreds of thousands of dollars for highly complex and multi-cavity steel molds. Per-part costs can be a few cents to several dollars, depending on size, material, and finishing.
As the cost is high on top, injection molding becomes extremely economical on a large scale. For companies that manufacture tens of thousands to millions of parts, no manufacturing process provides the same compromise of precision, repeatability, and cost-efficient results.
Smart design, careful material selection, and the right type of mold for your production requirements are critical to keeping costs under control, driving production times, and quality as high as they should be. With proper planning, injection molding can be used to produce parts of world-class quality at very competitive prices.