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    September 11, 2023

    What Is Injection Molding? Plus, Benefits and Tips for Success


    Injection molding is a great way to quickly and affordably make millions of identical parts each year. However, there are a lot of ins and outs of running a high-quality injection molding operation. In this quick guide, you’ll learn all about injection molding. Our experts at Rapid Axis will also give you some benefits and tips for success to ensure you have the best results in your next injection molding project.

    What Is Injection Molding, and How Does it Work?

    Injection Molding 1

    Injection molding is a form of manufacturing that involves pushing molten plastic into pre-made slots. The slots themselves are called cavities within the main mold, or tooling. The cavities are machined out of a big piece of metal, and they are a perfect negative of what your final product will look like.

    This negative image is filled, then the plastic starts to cool and harden. Once it’s hard enough, the mold will split open and push out the solid, plastic piece. Just like that, you have a finished product.

    The mold halves will then close again, another round of molten plastic will be pushed in, and the process will continue.

    For smaller parts, this full process can take less than a minute for a finished part to be created from scratch.

    Injection molding machines typically run around the clock and can easily make millions of units each year.

    Benefits of Injection Molding

    Why do so many people choose injection molding? There are a number of benefits:

    It’s a Low-Cost Option for Bulk Manufacturing

    When it comes to bulk manufacturing of plastic parts, there is no option that’s as affordable as injection molding. It might cost a few pennies for each product, including the operational cost and material cost.

    The only big cost is the upfront tooling cost. However, this cost gets diluted as you make more and more units. Over time, you’ll see a big reduction in your per-unit costs, making it the most affordable option for bulk plastic production.

    Much Faster Turnarounds Than Traditional Machining 

    We mentioned that a single injection molding machine can create millions of units each year for your company. This scale of production is unmatched by any other traditional machining option. Even a high-tech CNC milling machine running non-stop can’t keep up with this incredible production rate.

    If you need lots of parts each year and you don’t want to overpay, then injection molding is the clear path forward.

    Improved Tolerancing and Precision on Each Part

    Since each part is made out of the same mold and tooling, you’ll be able to achieve some incredible tolerancing and precision. Injection molding is one of the most repeatable fabrication methods, and you don’t need to pay for high-precision manufacturing for each unit.

    As long as the tooling was manufactured by a high-quality shop and the injection molding is run by a reputable company, your finished parts will be dimensionally identical.

    Tips for Success with Injection Molding 

    If you want to start making parts with an injection molder, keep these tips in mind. In this section, our experts will show you how to find more success in your injection molding undertaking. 

    Pick an Injection Molding Shop with Experience

    It cannot be overstated enough: you should never work with an injection molding shop that doesn’t have a lot of experience. Sourcing the raw material, understanding flow rates, and knowing how to run the temperature perfectly can make or break the reliability of each injection molding machine.

    For the best results, you should only pick a shop that has plenty of experience, like our team at Rapid Axis. 

    Understand Material Differences Before You Get Too Far

    The material that gets melted and pushed into the tooling is ultimately what your parts will be made out of. However, slight material differences can make a huge difference in each mass-production run. If one material is more abrasive, you’ll need to replace your tooling sooner. If another material has a higher melting temperature, you’ll have to recalibrate the injection molding machine.

    The best advice we can offer is to do your homework when it comes to material differences before you get too far. Try reaching out to a knowledgeable injection molding shop and asking them for some advice.

    Triple Check the Tooling Design Before Starting

    The tooling is the biggest cost of any injection molding operation, and it can cost $100,000 for even a simple design. Our advice? Triple-check your tooling design before you get started.

    It’s really hard to adjust the cavity or tooling after it’s fabricated. A big adjustment usually comes with another massive invoice and long lead time.

    Make sure the design is perfect before spending all of this money and time.


    As you just learned, injection molding is the gold standard when it comes to mass-producing plastic parts at affordable pricing. It allows you to get tons of parts delivered to your warehouse without overpaying for manufacturing.

    If you want the best results, consider working with Rapid Axis. We are a full-service machine shop that also offers around-the-clock injection molding services. We can meet your production schedule and keep your costs down in each run. Get a free quote today

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