Custom Plastic Injection Molding

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Stack Plastics, Inc. is a custom plastic injection molding company specializing in engineering thermoplastics, elastomers, and exotic resins, including PEEK, Delrin®, and more. We offer expert service throughout the entire development process of your injection molded products, from conception to prototyping to mass production.

Comprehensive Injection Molding Capabilities

Stack Plastics is an ISO 13485:2003 certified company with more than 20 years’ experience in custom plastic injection molding.

Based in the Bay Area of California, we specialize in injection molding for medical device components, but also supply parts, components, and assemblies for a number of industries and applications. We create plastic injection molded parts for everything from consumer products to aerospace components.

We provide a wide variety of custom plastic injection molding services and secondary services to give you the best quality products and the best customer service around. Our molding and value-add processes include:

Custom Injection Molding for Plastic Parts & Components

Our plastic molding and production services are completely customizable to the needs of your project, to ensure that the end products you receive meet your exact specifications.

Stack Plastics can produce prototypes, short-run development parts, and full production runs with quantities in the millions. From the simplest designs to the most complex, we can deliver high quality, high precision parts for any project. 

Contact Us for Custom Injection Molding & More

Contact Stack Plastics for a quote on your custom plastic injection molding project. Whether you’re in California or across the country, we’re ready to put our experience and capabilities to work for you.

Industries Served


With years of experience and advanced injection molding capabilities, Stack Plastics can deliver high precision, tight tolerance parts for the medical device industry. Using micro molding, insert molding, and other processes, will can provide the ideal injection molding solution for your needs. We are ISO 13485 certified for medical device component manufacturing.


Few industries require greater precision or tighter dimensional tolerances than aerospace. Stack Plastics uses proven injection molding techniques and state-of-the-art technology to produce precision molded aerospace parts and components that match our customers’ exact designs, with perfect repeatability from the first piece to the last


From level sensor floats to wine bottle openers and beyond, Stack Plastics has the injection molding capabilities to produce a broad range of consumer products. We utilize a variety of molding processes and thermoplastic materials and resins to create custom molded parts, components, and complete products for customers in all consumer markets.