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Injection Molding

Protomold Injection Molding offers low- to mid-volume part production from real engineering-grade thermoplastic, liquid silicone rubber and metal materials in less than three weeks. Protomold is often used for prototyping, shortrun manufacturing up to 10,000+ plastic parts and bridge tooling before moving to large-scale manufacturing. Along with plastic injection molding, our quick-turn metal injection molding (MIM) and liquid silicone rubber (LSR) molding processes produce quantities of 25 to 5,000+ stainless steel and LSR parts.
25 to 10,000+ parts
Shipped in 1 to 15 days
Molds start at $1,495

Plastic Injection Molding

Protomold plastic injection molding part example
Rapid injection molding uses the industry standard production process for parts, so it’s an excellent predictor of manufacturability when you move to large-scale production.

Liquid Silicone Rubber Molding

Protomold liquid silicone rubber part example
LSR molding is a thermoset process that mixes a two-part material together, which is then heat cured in the mold to produce a final part.

Metal Injection Molding

Protomold metal injection molding part example
Metal injection molding is a good low-volume bridge from machining to high-volume manufacturing of stainless steel parts.
Why Injection Molding?
Protomold stocks hundreds of thermoplastic resins that offer a variety of benefits for many different applications and industries. Metal and liquid silicone rubber provide additional material options. Here are some of our more frequently used injection-molding materials:
See full list of materials
  • ABS
  • Acetal
  • Acrylic
  • HDPE
  • LDPE
  • Nylon
  • PBT
  • Polycarbonate
  • Polypropylene
  • TPE
  • TPU
  • PEEK
  • PEI
  • Liquid Silicone Rubber
  • Stainless Steel


Small quantities of prototypes are often manufactured through our machining or additive processes, but injection molding is also utilized for a few reasons. Product developers can get a short run of parts made in real plastic, metal and liquid silicone rubber materials while simultaneously vetting a part design for moldability.
Protomold prototyping


Bridge tooling helps fill the manufacturing gap that occurs while waiting three to four months for production tooling to be ready. Our injection-molding process uses aluminum molds to quickly and efficiently produce a run parts for pilot production or market testing before large-scale production begins.
Protomold tooling


If volume needs don’t justify expensive steel production tooling, Protomold can supply low- to mid-volume production parts made in engineering-grade materials that meet full manufacturing requirements. Multi-cavity aluminum molds can be very cost effective, and we ensure that the tools last for the life of a project.
Protomold production
Protomold suite of services
Proto Labs manufacturing processes can take your product from idea to market launch fast. Injection molding is often used towards the end of the prototyping cycle when low-volume production begins.
Automated Interactive Quotes
When you have a 3D CAD model ready, simply upload it to receive an interactive quote within hours that contains free moldability analysis and pricing information. We accept all major 3D CAD file formats. See accepted file formats.
Accepted file formats for upload:
• IGES (.igs)
• STEP (.stp)
• SolidWorks (.sldprt)
• ProE (.prt)
• Parasolid (.x_t and .x_b)
• ACIS (.sat)
• AutoCAD (.dwg, 3D only)
• Autodesk Inventor (.ipt)
• Compressed folders (.zip)
“I have been a machinist for over 30 years and I have machined molds, but now that I am involved the designing process, Proto Labs’ design tools and support was like having my own mold designing team to bring our product to market.”
— Darrell Freeman, Blue-White Industries Ltd
A properly equipped tool belt of resources can prove invaluable no matter what stage of production you’re in. Our website contains a library of helpful content and free design aids.
Protomold plant floor