CustomPartNet
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October 15, 2026
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Updated October 15, 2026
A good first step is to filter your supplier list by the capabilities your project actually needs, such as experience with engineering plastics, quality certifications like ISO 13485, or cleanroom molding. Location also matters. A supplier close to your assembly site can reduce shipping costs and shorten lead times, which is especially useful during prototyping and design verification when you may need several quick iterations. For regulated products, the supplier you choose can be just as important as the part design itself. It also helps to review sample parts before you commit. Samples show real surface quality, feature detail, and consistency in a way a capabilities list cannot. Browse our supplier network on the right to compare qualified suppliers, examine sample parts, and request quotes.
Injection molding is the most commonly used manufacturing process for plastic parts, and it is well suited to medical components that must be produced in large quantities with consistent quality. The process requires an injection molding machine, raw plastic material, and a mold. The plastic is melted in the machine and injected into the mold, where it cools and solidifies into the final part.
Each cycle is short, typically between 2 seconds and 2 minutes, and consists of four stages:
Clamping: The two halves of the mold are securely closed by the clamping unit. Enough force is needed to keep the mold shut during injection, otherwise flash can form on the part.
Injection: Plastic pellets are fed into the barrel, where a reciprocating screw moves the material forward while heat and pressure melt it. The molten plastic is then injected into the mold, and the pressure buildup packs and holds the material in the cavity.
Cooling: The plastic begins to cool as soon as it touches the mold surfaces and solidifies into the shape of the part. The mold cannot open until the required cooling time has passed.
Ejection: The mold opens and an ejection system pushes the part out. The mold then closes and the cycle starts again.
Once molded, parts typically need some post processing, such as trimming runners or flash. For thermoplastics like acetal, scrap can often be reground and mixed back in at a controlled ratio, though many medical programs restrict or prohibit regrind, so it is worth confirming your requirements early.
POM, commonly known by trade names such as Delrin and Celcon, is a strong, rigid engineering plastic that is widely used for precision mechanical parts. It is a popular choice for medical devices because it offers:
High strength and stiffness
Excellent fatigue resistance for parts that flex or cycle repeatedly
Excellent creep resistance, so parts hold their shape under sustained load
Low friction and good wear resistance, ideal for moving parts
Good chemical and moisture resistance
Tight dimensional control for precision features
Medical grades available for applications requiring biocompatibility documentation
Low to medium material cost compared to many other engineering plastics
POM is naturally opaque white, and colorants can be added when you need color coding or brand matching.
The mold is the custom tool that forms your part, and it is usually made of steel or aluminum. The two main components are the mold core and the mold cavity, and the space between them forms the part cavity that is filled with molten plastic. Multiple-cavity molds are common when volumes are high.
Tooling cost is influenced by:
The size of the part envelope and the projected area of the cavity
Part complexity and feature count
Side-actions, lifters, or unscrewing devices
Tolerance and surface roughness requirements
Expected production volume, since higher volumes call for a higher class of mold
Medical device components often call for:
Hardened tool steel for long production runs
Multi-cavity tooling with balanced runner systems
Hot runner systems to reduce waste
Tight tolerances on gears, snaps, and mating features
Careful venting and gate placement for consistent fill
Draft angles of 1° to 2° and uniform wall thickness to support clean ejection and uniform cooling
Since POM shrinks as it cools, good mold design and process control are essential for holding tolerances on critical dimensions.
POM injection molding is used across the medical industry to manufacture:
Drug delivery device mechanisms, such as pen injector components
Inhaler components
Gears and drive components for infusion pumps
Surgical instrument handles and components
Dental instrument parts
Valves and fluid handling components
Latches, clips, and housings for diagnostic equipment
Bearings, cams, and slide guides
Components for laboratory automation equipment
California suppliers support prototype and production programs for medical device OEMs, startups, and contract manufacturers throughout North America.
POM combines strength, stiffness, fatigue resistance, and low friction in one material. That makes it a strong fit for small mechanical parts like gears, clips, and sliding components that need to work smoothly over thousands of cycles.
Tooling costs typically range from $5,000 to $100,000+ depending on part complexity, number of cavities, and production volume. Per-part costs depend on part size, material consumption, cycle time, and annual volume. Material cost for POM is generally low to medium.
Yes. Several material suppliers offer acetal grades intended for medical use, along with documentation to support biocompatibility testing. Your own testing and regulatory requirements still apply, so confirm the grade and paperwork with your supplier ahead of time.
It depends on the method. Acetal generally holds up well to ethylene oxide, but gamma radiation can degrade it, and steam sterilization performance varies by grade. Verify the sterilization method against the specific material grade before finalizing your design.
Typical tolerances range from ±0.005" to ±0.020" depending on geometry, material grade, and tooling quality. Critical dimensions may require tighter process controls. Always verify achievable tolerances with your supplier ahead of time.
Many medical device programs look for ISO 13485 certification, documented process validation, lot traceability, and cleanroom molding capability. Requirements vary by device class, so confirm expectations with your supplier early.
Injection molding is most economical for medium to high production volumes because tooling costs are spread over more parts. Production runs commonly range from thousands to millions of parts.
Get competitive quotes from California injection molding suppliers experienced with acetal medical components. Upload a CAD file, drawing, or product concept and receive quotes from qualified suppliers matched to your project requirements.
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