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Plastic Gears in Tools

DEWALT 20-Volt Li-Ion Cordless Brushless Compact Drill
Model # DCD790D2

Metal gearing has been used in gear systems like mechanical wrist watches, vehicle transmissions, and in power tools for a long time. Modern high strength plastics offer some advantages over metal that you might find surprising.

I purchased a compact brush-less lithium ion drill driver made by DeWalt from Home Depot recently. Someone later told me that I got the one with plastic gears because of where I purchased it. Plastic gears sounded bad to me so I looked them up online to learn more about modern engineered plastics. Much to my surprise I found that engineered plastics can actually outperform metal in a number of unique ways in tools and gearing systems.

Engineered plastics from companies like BASF like the ones used by DeWalt offer designers attractive material features that turn out to be great in hand held battery operated power tools, guns and other high performance compact applications. These same "high tech" plastics are used extensively in the construction of "smartphones" and "laptop" computers.

High Performance Plastic Gearing System Advantages

- Intrinsic lubricity

- Reduced friction
- Reduced rotational inertia for better performance
- Improved acoustical dampening
- Electrically insulating
- Ultra high-precision injection molding eliminates costly machining
- Surface profiles and textures not possible with metals
- Reduced weight
- Greater energy efficiency
- Reduced carbon footprint
- Lower cost
- Streamlined production
- Eliminates complex mechanical backlash
- Eliminates need for shaft alignment protection mechanisms
- Faster rapid starting and stopping
- Not prone to rust or corrosion
- Enhanced performance with fiber reinforcement
- Intrinsically impact resistant

Engineered plastics can actually outperform metals like aluminum and magnesium in power tool construction. Reimund Becht an engineering project manager of research and development at DeWalt Professional Engineering in Idstein Germany said that engineered plastics offer a range of advantage desirable in power tool applications that were previously unavailable with classical metal system designs. He mentioned BASF's Ultradur B4300 G6 plastic when speaking about the use of engineered plastics in DeWalt tools, noting that this material offers very high mechanical precision, stiffness and dimensional stability that simplify construction making the overall design more robust, lighter and less complex, allowing the entire tool to become more compact while also offering acoustical dampening behavior that is fundamentally superior to that of metal.

In the case of the power tool that I purchased, DeWalt combined a brush-less motor, Lithium NMC batteries, and engineered plastics to produce a compact, ultra light, high performance drill driver with great torque, improved run time, and reduced mass for less arm strain. The engineered plastics (several kinds) used in the tool give it advantages that stem from the material advantages offered by advanced plastics noted in the list above.

While I was a little worried about "Plastic Gears" at first, I found great relief in learning more about engineered plastic gears and gearing systems. I learned a lot about plastics that I was never previously aware of as a result of this brief inquiry into DeWalt power tool engineering.

I am not a contractor and imagine that this DeWalt engineered plastic tool will hold up fine for my small construction/ utility applications. I will first used this tool to build special DIY shelving to create more useful storage out of currently underutilized vertical overhead space in my tiny home.

I know about all of the weaknesses of Lithium Ion batteries and will make sure to shallow cycle and cool storage at half charge in order to get the most long term use out of the two 20v 2Ah batteries that came with the tool ^^ I will avoid over charging, deeply discharging and or overheating the batteries, things which would otherwise shorten their useful life. I am sure I can coax a few thousand cycles out of each pack by shallow cycling and keeping the temperature of the pack in the cool "human" range.


  1. I impressed very much by the high performance plastic gearing system advantages. All the advantages are really very precious. Thank you for your valuable information.