CustomPartNet
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September 24, 2026
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Updated September 24, 2026
Begin by filtering your supplier list down to the shops that fit your requirements, such as experience with acetal, the ability to hold gear-level tolerances, or specific certifications. Location is worth considering too, since it can influence freight costs and lead times. For precision gears, the supplier you choose can affect performance as much as the tooth profile itself, especially on high-volume programs or long-term partnerships. Reviewing sample parts is one of the best ways to judge fit. A molded gear shows you the surface quality and consistency a shop can deliver, which often tells you more than a list of specs. Use the supplier network on the right to compare Pennsylvania suppliers, look at sample parts, and request quotes.
Injection molding is the most commonly used process for making plastic parts, and it suits gears well. Once the mold is built, the same tool can produce thousands or even millions of identical gears with very little part-to-part variation. The process needs three things: an injection molding machine, raw plastic material, and a mold.
The plastic usually arrives as small pellets that are fed from a hopper into a heated barrel. A reciprocating screw moves the material forward, and it melts from a combination of pressure, friction, and heater bands around the barrel.
Once enough molten plastic has collected at the front of the barrel, the screw pushes it through the nozzle and into the mold cavity at high speed. Pressure builds to pack and hold the material in the cavity while it begins to cool.
The plastic solidifies as it cools, and the mold cannot open until enough cooling time has passed. The mold then opens, ejector pins push the part out, and the mold closes to start the next cycle. Total cycle time is typically between a few seconds and a couple of minutes, depending on the part.
Because each cycle repeats the same steps, injection molding can deliver consistent dimensions, detailed features, and a clean surface finish, all of which matter when a gear needs to mesh smoothly.
POM, also known as acetal and sold under trade names such as Delrin and Celcon, is a popular choice for molded gears. It offers:
High strength and rigidity
Excellent fatigue resistance for repeated tooth loading
Excellent creep resistance to hold shape under sustained load
Low friction and good wear performance for sliding contact
Resistance to moisture and many chemicals
Good dimensional stability for parts with tight fits
Low to medium material cost compared with many engineering plastics
The mold is a precision-machined tool, usually made of steel or aluminum, and its cavity forms the shape of the finished gear. The two main pieces are the mold core and the mold cavity, and the space between them becomes the part.
Tooling cost is driven by:
Size of the part envelope, which sets the mold base
Projected area and depth of the cavity
Number of cavities
Feature count, tolerances, and surface roughness
Side-actions, lifters, or unscrewing devices
Expected production quantity, since higher volumes call for a higher class mold that resists wear
Gear programs often call for:
Accurate cavity machining to reproduce the tooth form
Cavity dimensions that account for POM's shrinkage
Balanced gating so the gear fills evenly and stays round
Uniform wall thickness and well-placed ribs to limit warping
Consistent cooling to avoid distortion
Multi-cavity tools to keep piece prices down at volume
POM gears and related drive components are used across many industries, including:
Small appliance gearboxes
Printer and office equipment drive trains
Power tool components
Actuators and motor-driven assemblies
HVAC damper and vent mechanisms
Automotive seat and window mechanisms
Valves and flow control components
Cams, rollers, and slide guides
Bearings and bushings
Rotors and small mechanical drives
Pennsylvania suppliers support prototype and production programs for OEMs, startups, and contract manufacturers throughout North America.
POM combines strength, rigidity, fatigue resistance, and creep resistance with low friction and good wear behavior. It also stays dimensionally stable and costs less than many other engineering plastics, which is why it is a go-to material for gears that replace metal in lighter-duty applications.
Tooling costs commonly range from $5,000 to $100,000+ depending on part size, complexity, number of cavities, and required quantity. Per-part costs depend on material weight, cycle time, machine size, and annual volume.
General injection molding tolerances often fall between ±0.005" and ±0.020", depending on the geometry, material grade, and tooling quality. Gear tooth accuracy usually calls for tighter control, so it depends heavily on gear size, tool build quality, and process consistency. Always confirm achievable tolerances with your supplier before finalizing a design.
POM shrinks as it cools, and the amount depends on wall thickness, gate location, and how evenly the part cools. Experienced molders size the cavity to compensate and use uniform wall thickness and balanced cooling to keep the gear round and the teeth consistent. Non-uniform cooling is a common source of warping.
Yes. POM is offered in a variety of grades, including reinforced grades and grades with added lubricants for improved wear performance. Your supplier can help you match a grade to your load, speed, and operating environment.
Yes. Many Pennsylvania suppliers offer design-for-manufacturing feedback, prototyping, tooling, pilot production, full-scale manufacturing, assembly, and packaging.
Injection molding becomes more cost-effective as volume increases, because the tooling investment is spread across more parts. Programs typically range from a few thousand gears to millions of parts over the life of a tool.
Get competitive quotes from Pennsylvania injection molding suppliers experienced with POM gears and other precision components. Upload a CAD file, drawing, or product concept and receive quotes from qualified suppliers matched to your project requirements.
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