Injection Mold Tool - Cost Considerations

Crunching the numbers for plastic injection mold making

Are you doing your due diligence to budget for prototyping or production runs and avoid sticker shock down the road? Xcentric is a plastic injection molding manufacturer that bakes maximum efficiency into every mold we create here in Michigan. We do it in-house while always having access to common materials for tooling and injection-molded parts or sourcing any material you need for your project. That means we can start production cycles faster than other mold makers and take the sting out of considerable costs for you.

When bringing clarity and accuracy to plastic injection molding costs, these will be determined for every project on a case-by-case basis. Ballpark figures may be anywhere between $2,000 to over $50,000. More precisely, we would be happy to do the math for your molding project based on what you share with our specialists.

Materials used for plastic injection molding

Tool steel and aluminum are go-to materials for injection molds. Which one you choose for your tooling will greatly impact the costs. You will need to make a heftier investment than aluminum molds for tool steel molds, as they require tedious, labor-intensive machining and benching processes.

Aluminum molds are way more affordable and have unmatched thermal conductivity, which can be super-efficient for other molding processes, including PP and ABS plastic injection molding. But that doesn’t mean you should go for aluminum for every project to save money. In some cases, investing in multi-cavity steel molds is more efficient, even though it involves paying more initially. However, they are second to none when used as hard-wearing tooling for high-volume production runs, reducing the need to replace your molds due to wear and tear and helping you minimize piece costs in the long term.

Mold features

Xcentric is no stranger to plastic injection molding services with advanced tooling features. Depending on the components to be injection-molded and your design requirements, we can either produce a standard mold or a customized version upgraded with:

• Ribbing
• Inserts
• Undercuts and over molds
• Additional threads
• Extra cavities
• Other features to achieve specific tolerances (tighter than +/- 0.005”)

Custom plastic injection molding with extra mold features involves higher costs than standard tooling. This also applies to custom surface finishes, which you can request for your molds.

How to reduce plastic injection molding costs

Going over your project requirements with the Xcentric team is the first step to discovering cost-saving options for your injection molds. When talking this through, we will focus on:

• Whether you can simplify product design features to reduce unnecessary mold undercuts, inserts, ribbing, etc.
• Practical options to reduce the size of the components to be injection-molded.
• Whether it is worth cutting corners on surface finishes for parts that do not eat into the visual appeal of the entire assembly.
• How urgently you need injection molds, and whether you should avoid expedited delivery costs.

Whether you are interested in reliable tooling for plastic injection molding or other materials, our experts will walk you through the best options while considering your budget constraints.

The result is an extremely efficient process resulting in delivery of injection molded components in less than fifteen (15) business days on average at a very competitive price.  Factors affecting the cost of an injection mold are discussed in this section. 

Factors that contribute to injection mold tool cost: 

Custom injection molds can be very expensive to manufacture.  One of the key factors that drives the cost is the tool material selection. Typically, injection molds constructed out of tool steel cost more than double than that of aluminum. This is due to the much slower machining process required for steel, and the slower manual benching process to complete the molds prior to molding.  High volume projects (millions of components) normally require tool steel due to its wear resistance.   

Given the advancements made in aluminum alloys, higher grade aluminum such as QC-7, QC-10 or aircraft grade aluminum close the gap between the durability of steel and aluminum while retaining the cost and machinability advantages of aluminum. Today, aluminum molds can produce hundreds of thousands of parts and maintain accuracy and surface finish.  In addition, when molded parts require highly abrasive materials, aluminum tools can be coated or engineered with steel inserts for high wear areas of the tool. 

When it comes to the molding process itself, aluminum tools can offer faster molding cycles due to better heat dissipation for cooling, reducing the longest portion of the molding cycle.  Shorter cycle times equate to lower piece part prices.   

Other factors driving injection mold tool cost:

The cost of plastic injection molds depends on a wide range of factors such as: the number of cavities, size and complexity of the parts, number of parts to be molded, surface finishes, and textures.   

Consider the following when designing your part for injection molding as these will have an impact on pricing:

• Delivery Time – Xcentric has built its reputation around delivering injection molded parts in low to medium volumes extremely quickly compared to traditional mold makers.  Starting from a standard delivery time of fifteen (15) business days to first molded samples, two faster levels of expedited production are available.  Expediting fees are substantial however, so it is important to properly assess the value of requesting this level of service. 
• Annual Volume – Volumes over 100,000 annually typically require multi-cavity tooling.  This will increase the tooling price significantly but will reduce the piece price by as much as 60% per additional cavity.  For this reason it is important for our clients to specify annual production volume accurately at the project inception to maximize production rate and minimize piece part pricing. 
• Undercuts– Although we can handle unlimited undercuts in the part geometry, these add cost and complexity to the tools.  Xcentric’s sales engineering team will assist in evaluating a part for moldability and can suggest ways to minimize undercuts and other mold features that add cost. 
• Inserts and Overmolds – Molded components requiring metal inserts or overmolded features using a second material on a molded substrate are daily business for Xcentric.  These features require additional work and process care to assure a high quality outcome, which naturally increase pricing.  It is important to discuss the project objectives with our sales engineers to assure we consider the needs of the final application, whether prototype or production, when producing parts with these features to minimize cost implications, particularly if larger volumes will be required. 
• Surface Finish – Xcentric offers surfaces finishes from “as machined” to nearly optically smooth.  Generally speaking the finer the finish the more expensive due to the additional labor and time involved to achieve best possible finishes.  Tip: If the molded part is to be hidden in an assembly, money can be saved by choosing a 320-sand paper finish. 
• Part Complexity – Part complexity can drastically increase the cost of a tool.  The more faces or surfaces in the CAD model has, the higher the cost.  Consider this when adding blends or unneeded features.
• Mold Construction Materials – We will assist you in determining the best materials to build your plastic injection mold.  This is why we offer a lifetime mold warranty because we stand behind our work and engineering.