Custom Plastic Injection Molding & Manufacturing

As an industry-leading custom plastic parts manufacturing company in Pomona, CA, the experienced team of manufacturing engineers at PEP assists clients in a variety of highly technical industries, from consumer goods to business to industrial.

Mold Manufacturing & Reverse Engineering

Using expertly developed critical thinking and deductive reasoning skills, the team of tool builders at PEP have the innate ability to develop and construct tools to comply with specific requirements in highly regulated industries, such as medical, aerospace, and agriculture.

Complex Plastic Component Assembly & Sonic Welding

The assembly team at PEP is experienced in every aspect of product assembly and the machining process, providing precise and accurate assembly while adhering to the essential standards of high-quality performance and seamless component integration.

JIT Services

With an onsite warehouse and efficient trucking system, we can provide support for all of your supply chain management needs, from storage to product distribution.

We can help take your product from CAD drawing to physical production

Our experienced team of plastic parts manufacturing specialists will take your product from initial CAD drawing to final delivery with innovative design, superior precision, and guaranteed accuracy. View the video below to get a glimpse of the dedicated team and supportive company culture at PEP.

Who We Are & What We Do

Founded in 1981, PEP has been an industry leader in custom plastic injection molding in the Greater Los Angeles area for over 40 years. With extensive experience in manufacturing high-quality custom plastic parts, the team at PEP remains dedicated to providing superior customer service and establishing long-lasting client relationships built on trust and integrity.

PEP is an AS9100D & ISO 9001:2015 , ITAR and FDA Certified Company, with the in-house capacity to manage every aspect of the custom plastic injection molding process. With application of highly technical scientific developments and advanced plastic parts manufacturing methods, we provide innovative engineering and design concepts that are both efficient and cost-effective for small volume and large volume production.

Experience The Best Custom Injection Molding Service In Pomona, CA

With 40 years of experience in the custom plastic parts manufacturing industry, our dedicated team will exceed your expectations with a unique combination of exceptional quality and competitive pricing. PEP will take your product from concept to completion, while remaining on time and on budget.

Our Services

Whether you are looking for low volume production, high volume production, or sample runs for product prototypes, we have the custom injection molding capacity to get the job done on time and on budget.

Injection Molding

We utilize the best injection molding methods to suit projects of every complexity, which are both cost-effective and scalable for high volume production of custom plastic parts.

Product Development

From initial concept to final delivery, our product development engineers will bring your product vision to life using the most advanced computer programs and efficient design software.


With an experienced team of product assembly specialists, PEP provides custom plastic parts assembly to meet all requirements and high-performance standards across a variety of industries.

Quality Control

With various stages of quality control during each product development process, the PEP team is committed to providing exceptional results that exceed our customers’ expectations.

Tooling Service

The team of design engineers at PEP are able to make tools with a high degree of precision and accuracy to serve our complex industries, designed to meet our customers’ exact specifications.

3D Printed Injection Molds

The majority of plastic products in the world today are manufactured by injection molding. However, fabricating molds can be prohibitively expensive and time-consuming. Fortunately, molds don’t always need to be machined out of metal—they can be 3D printed.

Tool Transfer

You invested in tooling and need to get good parts
that consistently are delivered on time.



With over 40 years of experience, we are experts in the highly technical process of aerospace plastic injection molding, with stringent testing and real-time data monitoring throughout production.


We have the capacity for high-volume manufacturing of plastic components for the agriculture industry, including use of commercial-grade plastics to meet the demand of highly regulated industry standards.


The team at PEP provides electronic parts manufacturing for complex high-precision electronic parts, using only the most durable materials to make components that are strong, reliable, and heat-resistant.


As an ITAR certified parts manufacturer, we have a specialized team of design engineers to ensure your defense weapon component can be seamlessly integrated to ensure optimal functionality and performance.


With both small volume and large volume production of automotive parts, we offer automotive clients OEM service and aftermarket part production, including implementation of five core quality control tools.


Verified by FDA and ISO certification, our medical parts manufacturing process takes place in a sterile environment to ensure no cross-contamination during highly sensitive medical equipment parts production.


Our in-house team of consumer goods manufacturing experts provides the best consumer product design, assembly, manufacturing, and packaging from start to finish, including printing and labeling services.


We are experts in tool building, process improvement, and reverse engineering, and can manufacture industrial parts to comply with standards across a variety of industries, using high-end plastics and precise dimensional measurements.

Our Valuable Customers






Manufacturing Plants

Our Certifications

Plastic Injection Molding Capabilities

Industries target Aerospace , Medical , Automotive , Defense , Electronic , Consumer , Industrial.
Material Expertise PEEK, ABS , Acetyl , Acrylic , Copolymer Polypropylene , HDPE/LDPE , Nylon , PEEK , Vectra , PET , Polycarbonate , Polyester , Polypropylene , Polystyrene , Polyurethane , ULTEM , Liquid Crystal Polymers
Product Capabilities Large Size parts, Medium-sized parts , Micro parts , Miniature parts , Small-sized parts.
Services Insert Molding , Over Molding, assembly , Mold Making , Kanban Program , Inventory Managed Shipment, Printing or decorating.
Production Volume Low Volume , Small Runs , High Volume , Large Runs , Sample Runs
File Formats AutoCAD (DWG) , STEP , UG , IGES , JPEG or JEPG , PDF , Solid Works (SLDPRT, SLDDRW, SLDDRT)
Shot Size 56g (min) – 4564.27g (max)
Clamping Force 38 tons (min) – 880 tons (max)
Number of Cavities 1 cavity (min) –48 cavities (max)
Tolerance (+/-) Down to 0.0001 in.

PEP is dedicated to high-quality production of your products from design to delivery.

Contact our experts to help bring your idea to market efficiently & cost-effectively.