For many decades, the primary material used for gears throughout various industrial applications was metal. In recent years, however, plastic has begun to take a larger and larger share of the gear market, now with uses across numerous industries and fields — why is this, and is this change likely to stick around?

At EnviroTech Custom Injection Molders, we’re happy to provide plastic injection molding services for a wide variety of industries that utilize gears regularly, from the energy industry to automotive, electrochemical, marine and numerous other application areas. As the true benefits of plastic gears are finally coming into focus across the industrial world, our orders in this area have gone way up. Why are more and more parts manufacturers choosing plastic gears instead of metal ones today? Here are several reasons.

They’re Lighter in Weight

First and foremost, plastic gears are simply far lighter than metal gears. Metal is extremely heavy; if you’ve ever spent any time working on an old car or motorcycle, then you probably know that all too well already. While this might make metal gears appealing for use in some applications (like automobile transmissions), it makes them almost useless for others (like turbines).

This problem is plain to see when you look at the weight of metal gears compared to plastic ones. A common metal gear might weigh eight or nine pounds, while an injection molded one is less than a quarter of that weight – and some grades of plastic can be even lighter than this.

The difference in weight can’t be understated, either; there’s a reason why NASA relied upon plastic gears when designing the landing gear for its Mars rover, Curiosity. A lighter product that provides the same level of strength and durability will always be preferable to a heavier alternative, and that is one of the primary reasons why plastic is overtaking metal in the gear industry.

Reduced Noise Levels

Another reason for manufacturers’ interest in plastic gears is noise reduction. Metal gears have a tendency to squeak, whine and even grind when they’re being used. While this might not seem like a problem, it can be extremely frustrating for individuals who use them on a regular basis — and also presents an unnecessary safety hazard.

Plastic gears, on the other hand, don’t make nearly as much noise and are far less likely to generate grating sounds that can be unpleasant or even damaging to the ears. This is particularly helpful in applications such as power transmission, where constant noise would otherwise impede productivity and put workers at risk of developing long-term hearing damage.

Shock and Vibration Limitation

Down similar lines, plastic gears are much more effective at limiting shock and vibration. Even the most powerful metal gears can’t compare with injection molded plastic when it comes to this area; as anyone who has used both types of gear will attest, plastic ones simply don’t experience as much shaking or shimmying as their metal counterparts.

This is especially helpful in applications such as oil and gas pipelines, where a lot of vibration can lead to equipment failure. Thanks to their low levels of shock and vibration, plastic gears make a perfect choice for use in this area; they ensure uninterrupted, reliable performance while also minimizing the risk of sudden failures.

Corrosion and Chemical Resistance

Gears will often be used in marine or other applications where water and moisture can be a huge issue. Metal gears, as we all know too well, will rust and corrode in the presence of water; this is an automatic death sentence for these parts.

Plastic gears, on the other hand, don’t experience corrosion or oxidation in such conditions, making them far more durable and reliable than metal components. This makes them a perfect choice for gearboxes and other parts used in ships, boats and even oil rigs — where moisture and salt-water exposure is par for the course.

Simple Performance

Lightweight, sturdy and durable, it’s hard to beat plastic gears when it comes to performance. Although they’ve been largely relegated to simple applications like drill presses and other such equipment up until now, it’s expected that these parts will see a surge in use throughout the gear industry as time goes on.

As more and more companies discover the difference between metal and plastic gears for themselves, demand will increase – resulting in an increased production of injection molded plastic gears. This is already evident from recent trends, which show a powerful rise in the use of these parts throughout numerous industries and markets.

Cost Factors

And finally, perhaps the most important reason why many manufacturers are turning to plastic gears over metal ones is cost. Metal gears might be (slightly) more durable and reliable, but plastic ones are simply much less expensive to produce.

For companies that need parts in large quantities on a tight budget, plastic is the clear answer; its affordability makes it possible to get replacement or additional gears without spending too much money. And because plastic gear manufacturing has improved an incredible amount in recent years, the gaps in quality between these and metal are not very large — or are even nonexistent in most cases. If you can get the same level of quality from plastic parts for a fraction of the cost, plus receive the other benefits we’ve already gone over here, the choice is a simple one.

For more on why plastic gears are threatening to overtake metal gears in many industries, or to learn about any of our plastic injection molding services, speak to the staff at EnviroTech Custom Injection Molders today.