Deciding Between Plastic and Metal

When designing a product, a key consideration is choosing which material to use for manufacturing. The decision is typically based on some of the following criteria:

  • Design requirements
  • Industry standards
  • Environmental concerns, including where and how the product will be used
  • Manufacturing costs

Both plastic and metal have advantages, but you may be surprised that both materials can offer heat resistance and strength. Below, we’ll outline each material’s benefits and drawbacks.

This piece is die cast aluminum. It is painted and has a rubber soft coat.


Metal is a great fit for some applications. Its properties include:

  • Heat resistance: Its higher melting point makes it suitable for high-temperature environments.
  • Strength: Durable metal is a good choice for structural parts and weight-bearing applications.
  • Versatility: Metal has many finishing options (anodizing, powder coating, etc.).
  • Variety: Choose from conductive copper as well as its alloys (brass, bronze, etc.), steel, aluminum, and more.

If made in large volume, metal products can be manufactured cost effectively. Large-volume production of metal parts is typically done using casting or forging. Metal products can also have attractive finishing options, such as anodizing or powder coating, with some limitations. For example, when casting a metal part, you cannot anodize it because the metallurgy of the material is affected by the casting process. This change in metallurgy makes the metal unable to accept the anodized finish, with poor results.

While metal products do have benefits, there are also several drawbacks. Metal parts often require post processes, which occur after the initial production process. A part may need to be milled, honed or ground after casting. This is because some features may not be able to be cast. These additional processes can add cost, which may be problematic for your overall budget. Depending on which metal you choose, metal may be more expensive than a comparable plastic material for a given application. Metal products are also often heavier than their plastic counterparts, which could affect the assembly process and freight costs for the final product.

During the design process of this piece, the customer was able to choose metal or plastic. They ended up going with plastic for this enclosure.


While there are some potential benefits to using metal for product material, you will find that many of the same benefits can be realized with plastic if designed and engineered properly:

  • Heat and fire resistance: Additives (such as BFR), can be used to make plastics heat or fire resistant.
  • Strength: Additives like fiberglass can increase the strength of plastic, making it similar to or even stronger than the same metal part design.
  • Cost: Plastic parts are also typically cheaper than their metal counterparts. Plastic prices are often cheaper per kilogram, and in most cases, plastic parts can be made more efficiently than in metal, requiring less post processing.
  • Material options: There are thousands of material options available. You can study and select the material that is perfect for your specific product and needs.
  • Color and finishing customization: Most plastics start out clear, and then your manufacturer can add colorant to the material to change its color, an advantage over metal parts. This means you have the ability to customize the plastic color for branding and aesthetic purposes. You can also choose from dozens of different textures and finishes for your plastic part.

Interested in learning more about different types of plastic? Check out our blog on bioplastic. Or our plastic injection molding process.

While metal may be the best choice for some applications, be sure to consider plastic for its versatility and cost benefits before deciding how to manufacture your product.