Why Manufacturers Are Shifting To Plastic (And Why You Should Too)

Metal materials are often associated with strength, premium, and quality. In early manufacturing, iron and steel were the mainstays of industrial processes. Today, more and more metal components are being replaced with other metals, and most popularly, plastic. If you have bought a new automobile or electronic device recently, you will feel the lightweight arising from the use of more durable plastics. The reward of this is fuel/energy economy and lesser cost. 

In today’s article, we highlight the key motivations for shifting from metal to plastic. At the end of this article, you should be able to decide if and when to make the shift, depending on the type of product and parts you manufacture.


Cost is a significant component in any size of product manufacturing. Many manufacturers have discovered that they can achieve the same value for appreciably less. With less energy consumption and labor effort, higher processability, and overall lower cost per kg, plastic beats metal materials when working with a tight budget. Choosing plastic could also mean a lower cost per part and higher profitability. In terms of processing, plastic materials are often made via injection molding. The process itself is relatively cheaper than metal forging and casting operations. When making injection molded parts in high volume, the tooling lifespan for plastic parts is significantly higher in cycles than metals.


Away from cost, plastic resins are significantly lighter than their metal components. This is usually very key for industries like automotive, aerospace, and even medical. In applications where weight is crucial, using plastic materials can lower the part’s overall weight without compromising significantly on strength.

Lower weight in vehicles, aircraft, and mechanical parts often translates into fuel economy, energy savings, and improved suspension and aerodynamics. 


Unlike metal parts and components that will rust and leak over time, plastic parts do not corrode. While metal parts can be stronger than plastic during initial installation or application, metals often become less effective, weaken, and fail over the years because of their exposure to moisture and water. In contrast, plastic material will not rust or degrade even when in contact with water or humidity. This is why plastic is usually preferred for making plumbing, pipe, and fitting components.

Where engineered thermoplastic is to be used, your business can benefit from the high strength, chemical, and corrosion resistance of plastic parts. In automotive applications, plastic parts are used in making bumpers because of their dent resistance. 


Plastic parts are generally easier to cut through than metal parts. Plastic resin is also easier processed than molten metal alloys. The improved machinability can make it easier to obtain intricate designs and shapes in plastic parts.


Plastic parts usually require minimal finishing operations that can be achieved during injection molding. Unlike their metal counterparts, they will naturally not corrode. They can also be colored or made to be transparent by simply picking the right types of resins. This reduced finishing cost can be a major component when comparing prices to metal parts piece by piece.

Other considerations 

Plastic holds other advantages over metal parts like noise and vibration dampening, various options, repeatability, and product lifespan. With plastic, designers can achieve shapes, lettering, and surface textures without many finishing operations. Plastic parts can also serve broader food-grade and medical applications than what is currently available with metallic elements.

Plastic assemblies can integrate assembly features into the components like snap-fits. As a result, the entire processing and assembly time of making your parts in plastic may be generally faster than metal parts. 

Final considerations

While more and more companies continue to tilt towards and adopt plastic parts as substitutes for metals, the primary criteria remain the suitability for your end application. Plastic has certain disadvantages. For instance, plastic parts have considerably lower strength than metals. They also suffer from shrink, expansion, creep, and fatigue. Plastic parts have low electrical conductivity and may degrade under the influence of UV-light.

Before concluding to shift or start with plastic parts, consider your product and the suitability of either group of materials for your product end-use. Still undecided, contact us here! 

Firstpart Injection Molding Services 

Firstpart can help you optimize your production, design, budget and supply chain to choose what is best for you. We boast of excellence, experience and diversity in plastic injection molding for making mass production volumes of various applications

Depending on your project, we can help you make low-cost or hardened steel tooling around budget, material and volume considerations.

Please contact us to get in touch with one of our experts and receive free quotes, design and finish suggestions on your next project right away! Work with us and allow us to manage your die casting and injection molding needs and help you transition from rock solid prototypes to excellently finished die-casted products.