Mastering the art of estimating injection mold costs could become your secret weapon. It sharpens your budgeting skills, offering you a clearer picture of where your money is going. Plus, it equips you with the knowledge to negotiate more effectively with mold suppliers.
Injection mold cost also guide you in making pivotal decisions for your injection molding project, such as determining the number of cavities and choosing the right mold steel. If your project require a large volume of parts, choosing a multi-cavity mold could significantly cut down your cost per part.
In this article, we will discuss the factors influencing the injection mold cost and how to estimate the injection mold cost.
Factors Impacting the injection mold cost
Part Size: The part size directly influences the tooling size. Large parts need large molds, which raises the plastic injection mold cost.
Part Complexity: The more complex a plastic part is, the more intricate the tool design must be. If the part has undercuts, the mold needs slides, lifters, a collapsible core, or an unscrewing system to release the undercut. Complex molds need the time, effort, and precision required in mold-making, increasing the injection mold cost.
Part Tolerances: Creating a mold that can produce parts with tight tolerances involves meticulous design and manufacturing processes. We have to use precision equipment to produce the molds with tight tolerance. It may also require additional testing and adjustment to ensure the final part meets the specified tolerances.
Part Surface: If the surface has to be high gloss polish, use S136 or S136H steel. Both the steel and polish manufacturing cost will be higher than technical polish. As for the texture, the MT texture is higher than the VDI surface.
Material Hardness: Plastic materials vary significantly in hardness. Some plastics, like PC or certain types of nylon, are more rigid and more abrasive, which can cause accelerated wear and tear on the mold. This wear may require frequent maintenance or mold replacement, increasing tooling, injection mold cost.
Temperature Requirements: Different plastic materials have varying melting points. For instance, high-temperature materials, such as PEEK and PEI, require the mold to withstand extreme heat, which can impact the choice of mold material, and, subsequently, the injection mold cost.
Chemical Composition: Certain plastics have additives or fillers like glass fibers, minerals, or other substances that can increase the wear and tear on the mold. The chemical composition of the plastic can also lead to corrosion of the mold, which can affect its durability and lifespan.
Flow Rate: The flow rate of the plastic material, i.e., how easily it can fill the mold, impacts the tooling price. Materials with lower flow rates can require molds with more precise heating and cooling systems, leading to a higher injection mold cost.
Creating two-color plastic components can be achieved through over molding or two-shot molding. The tooling cost for two-shot mold is higher than over mold. However, the unit part cost and quality of two-shot molding surpass those of over molding. If your project involves a high volume of parts, opting for two-shot molding can be more beneficial.
When it comes to parts with a thread, there are different considerations. If the volume is low, you can incorporate the thread manually using an insert to keep tooling costs down. Conversely, for high-volume production, it’s advisable to create an unscrewing mold. While this might result in higher mold costs initially, it leads to cheaper part costs in the long run, proving more economical.
Steel Quality: High-quality steels such as 1.2344 and S136, known for their durability and resistance to wear and tear, tend to be more expensive. However, they also ensure longer mold life, meaning fewer replacements or repairs. Lower quality steels might be less expensive initially but may not stand up to repeated use, leading to potentially higher costs in the long run.
Steel Hardness: The hardness of the steel directly impacts its wear resistance. Harder steel can endure more injection cycles, especially when molding abrasive materials, but it is also more expensive. Conversely, softer steel may be less expensive but might not withstand high-volume or long-term production runs.
Machinability: Steels that are easy to machine steels can reduce the time and labor needed to create the mold, lowering the cost. However, these steels offer more durability than those less machinable but are harder and more wear-resistant.
Corrosion Resistance: Some steels have better corrosion resistance, which is especially important when molding materials that could cause corrosive wear to the mold. While corrosion-resistant steels can be pricier, they can save maintenance costs and prolong the mold’s lifespan.
Heat Treatment: Certain mold applications may require specific heat treatments to the steel, such as hardening or tempering, to improve its performance properties. These treatments add to the overall cost of the mold.
Mold Size: The mold’s size directly correlates to its cost. Larger molds require more raw materials, machine time, and labor to produce, which result in a higher injection mold cost. The size also impacts storage requirements, with larger molds needing more space and specialized handling.
Part Volume: If the part volume is high, it is better to make it a multi-cavity mold instead of a single-cavity mold. Higher production volumes justify higher initial investments in more durable, high-quality molds. These molds can withstand repeated use without significant wear, making them cost-effective for large production runs.
Cycle Time: Cycle time – the time required to produce one part – can impact cost dramatically. A shorter cycle time allows more parts to be made per hour, reducing labor and energy costs per part. However, faster cycle times may require higher-performing (and often more expensive) molds. Therefore, balancing cycle time, mold cost, and production efficiency is critical for cost-effective injection molding.
Mold manufacturing location: The injection mold cost price in the USA and Europe is much higher than in China.
The composition of Injection mold cost
Injection Mold Cost = Engineering cost + Material cost + Manufacturing cost + Mold trial cost + delivery cost + profit
The engineering cost includes mold design, Moldflow analysis, CNC programming, and quality checks. Currently, the rate is around USD8 per hour.
Material cost = mold base + steel material (cavity, core, slides, and lifters) + electrode (copper or graphite) + mold component (ejector pins, ejector sleeve, and date code) + hot runner (optional) + hydraulic Cylinder (optional)
For example, the mold base material is S50C. Rough mold base price = Length(meters) * Width (meters) * Height (meters) * 7.85 * USD2.8
Manufacturing cost = CNC machining + heat treatment + EDM manufacturing + wire cut manufacturing + polishing + texturing + mold fitting
The cost of CNC Machining, EDM Manufacturing, and Wire cutting mainly depend on the machining equipment. High-precision machines lead to higher manufacturing costs. Machining manufacturing cost= machining cost per hour * machining time
Mold trial costs includes the cost of plastic raw material and injection molding process. Mold trial costs will be higher for high-temperature materials (like PEEK, PEI, and PSU) or specialized processes such as two-shot molding or gas-assist molding.
Delivery cost includes the cost of sample delivery and mold delivery.
Estimating plastic injection mold costs can be a complex task, breaking down the costs and understanding each contributing factor can simplify the process of estimating plastic injection mold costs.
This comprehensive understanding will enable you to manage your project costs more effectively and ensure you make informed decisions in your injection molding projects.
How to get an accurate mold price from the mold manufacturers in China?
Securing an accurate mold price from Chinese mold manufacturers requires specific information. Here’s what you need to provide when requesting a quote:
1, 2D and 3D part drawings – These details help the manufacturer understand the plastic material, color, tolerance, and surface requirements.
2, Cavity number – The total number of cavities in the mold.
3, Tool steel
Full hardened mold(H13, S136, 1.2344)
Pre-hardened mold(1.2738H, 1.2718H)
Soft Mold( Aluminium)
4, Type of mold
hot runner mold or cold runner mold
over mold or two shot mold
unscewing mold or thread by insert
If the above information is not readily available, you can provide the 3D part design and total part volume. The mold makers could help you to provide the best tooling solution.
With the average mold cost hovering around USD5,000, prices can vary from as little as USD3,000 to USD7000. So, it’s important to get detailed quotes from different mold makers to compare mold sizes, tooling life, and prices.
Stebro Mold is a full services custom mold maker and injection molder based in China. We specialize in producing high-performance plastic tooling and injection-molded parts for export. You can get a detailed quotation sheet with a DFM report from us within 24 hours.
The next article will explore ways to reduce the injection mold cost without compromising the quality.