For OEMs, engineers, and purchasing teams evaluating plastic injection molding companies in California, supplier selection involves far more than comparing piece price. Certifications, engineering support, tooling, cleanroom capabilities, material expertise, production capacity, secondary operations, quality systems, and industry experience can all affect program performance.
For companies looking for a Southern California manufacturing partner, Hi-Rel Plastics Riverside combines 40+ years of plastics manufacturing experience with ISO 9001:2015, ISO 13485:2016, and AS9100 Rev D quality systems. Its capabilities extend from custom plastic injection molding and engineering support to mold manufacturing, cleanroom production, Liquid Silicone Rubber (LSR) molding, secondary operations, assembly, and other plastics manufacturing processes.
That combination makes Hi-Rel particularly relevant for medical, aerospace, defense, electronics, industrial, automotive, and other quality-sensitive applications where buyers may need more than a conventional molding supplier.
Request a Quote to discuss tooling, molding, cleanroom, material, assembly, or production requirements with Hi-Rel Plastics & Molding Corp.
This guide also compares nine other established injection molding manufacturers with California operations. The companies are not presented as an independently audited numerical ranking. Instead, they represent notable California injection molding resources buyers may consider based on publicly available capabilities, certifications, experience, and manufacturing services.
| Company | California Location | Key Certifications / Registrations* | Manufacturing Highlights |
|---|---|---|---|
| Hi-Rel Plastics & Molding Corp | Riverside | ISO 9001:2015, ISO 13485:2016, AS9100D | Injection molding, LSR, cleanroom manufacturing, tooling, engineering, secondary operations, assembly |
| JG Plastics Group | Costa Mesa | ISO 9001:2015, ISO 13485:2016, AS9100D, ITAR | Precision molding, thermoplastic and thermoset molding, mold making, cleanroom molding, assembly |
| Westec Plastics | Livermore | ISO 13485:2016 | Precision molding, two-shot molding, tooling, insert molding, overmolding, cleanroom manufacturing |
| JATCO Incorporated | Modesto | ISO 9001:2015 / ANAB-accredited certification | Injection molding, engineering, tooling, assembly, decorating, packaging, warehousing |
| Plastikon Industries | Hayward | ISO 9001 / ISO 13485 at applicable facilities | Injection molding, tooling, product development, automation, healthcare manufacturing |
| Distinctive Plastics | Vista | ISO 9001:2015, ISO 13485:2016; FDA registered, UL listed | Multi-shot molding, insert molding, in-mold decoration, cleanroom manufacturing, assembly |
| Aprios Custom MFG | Vista | ISO 9001:2015, ISO 13485:2016 | Precision molding, DFM, tooling, medical manufacturing, ISO Class 8 cleanroom |
| Canyon Graphics | San Diego | ISO 9001 | Injection molding, multi-shot overmolding, insert molding, IMD, printing, thermoforming |
| Fabricated Extrusion Company / FABEXCO | Stanislaus County | Verify certification requirements directly | Injection molding, large-part molding, engineered resins, automation, extrusion, tooling, engineering |
| Universal Plastic Mold | Baldwin Park | ISO 9001 | Injection molding, large-part molding, engineered resins, assembly, packaging |
*Certifications, locations, capabilities, company size, and years in business are based on publicly available manufacturer information and industry directory data available in 2026. Buyers should verify current certifications and project-specific capabilities directly before supplier qualification.
Hi-Rel Plastics & Molding Corp. is a Southern California custom plastics manufacturer supporting customers from product development and DFM through tooling, molding, secondary operations, assembly, packaging, and ongoing production. For buyers specifically researching Hi-Rel Plastics Riverside, the company’s strongest differentiator is the breadth of manufacturing support available from one supplier.
Hi-Rel operates under ISO 9001:2015, ISO 13485:2016, and AS9100 Rev D quality systems and supports demanding medical, aerospace, defense, electronics, automotive, industrial, and commercial programs.
Hi-Rel works with commodity, engineering, and high-performance thermoplastics including materials such as PEEK, PEI/ULTEM, PPS, PPSU, PES, PVDF, LCP, PBT, polycarbonate, ABS, acetal, nylon, glass-filled nylon, TPU, TPE, PP, HDPE, and other specialty materials.
For medical programs, Hi-Rel also supports medical device injection molding alongside controlled-environment manufacturing, tooling, assembly, and production support.
Hi-Rel’s capabilities are relevant to OEMs operating in:
Medical devices • Aerospace • Defense • Automotive • EV • Electronics • Communications • Industrial equipment • Consumer products • Cosmetics & personal care • Construction • Agriculture
The combination of three major quality certifications, broad material knowledge, multiple plastics manufacturing processes, cleanroom capabilities, and turnkey support positions Hi-Rel Plastics Riverside as an option for OEMs that want to consolidate engineering, tooling, molding, secondary operations, and assembly with one California manufacturing partner.
Request a Quote for a new mold, transferred tool, injection molding program, cleanroom project, LSR component, or turnkey plastics manufacturing requirement.
JG Plastics Group has provided plastic manufacturing solutions since 1975 and serves medical, aerospace, defense, electronic/connector, and consumer markets. Its published capabilities include thermoplastic and thermoset molding, precision mold making, insert molding, overmolding, cleanroom manufacturing, assembly, and secondary operations.
Best suited for: medical, aerospace, defense, and highly engineered precision components.
Westec Plastics specializes in high-precision custom injection molding, with particular experience in medical and biotech applications. Its capabilities include two-shot molding, insert molding, overmolding, tooling, cleanroom manufacturing, secondary operations, and advanced inspection.
Best suited for: medical devices, biotech, electronics, and precision components requiring strong tooling and process control.
JATCO provides injection molding together with product design, engineering, tooling, secondary operations, assembly, packaging, warehousing, and distribution. Its manufacturing model may appeal to OEMs looking to combine molding with broader downstream production support.
Best suited for: programs requiring molding plus assembly, packaging, warehousing, or distribution services.
Plastikon Industries provides injection molding, mold design and tooling, prototyping, engineering, automation, and specialized healthcare manufacturing services. It operates at a larger organizational scale than many regional California molders.
Best suited for: larger OEM and healthcare programs requiring extensive manufacturing and automation resources.
Distinctive Plastics focuses on technical molding processes including multi-shot molding, in-mold assembly, in-mold decorating, in-mold labeling, insert molding, and medical manufacturing. It also publicly identifies ISO 9001:2015 and ISO 13485:2016 certifications.
Best suited for: complex multi-material components, medical devices, and products requiring advanced decoration or multi-shot processes.
Aprios Custom MFG provides precision injection molding, tooling, DFM, and contract manufacturing services from its California operation. Its capabilities include medical manufacturing and ISO Class 8 cleanroom injection molding.
Best suited for: medical-device programs, product development, tooling, and precision molding.
Canyon Graphics combines injection molding with product-decoration technologies such as multi-shot overmolding, insert molding, film insert molding, printing, thermoforming, precision cutting, and lamination.
Best suited for: consumer, electronics, and specialty components requiring molding combined with graphics or decoration.
FABEXCO combines injection molding with extrusion, engineering, tooling, automation, and large-part manufacturing capabilities. Its broader process range can be useful for industrial programs that involve more than one plastics manufacturing method.
Best suited for: larger molded components, industrial applications, and projects requiring both injection molding and extrusion capabilities.
Universal Plastic Mold provides custom injection molding, large-part molding, engineering and DFM support, tooling, assembly, finishing, kitting, packaging, and distribution. Its production capabilities are particularly relevant to large components and high-volume programs.
Best suited for: automotive, consumer, and industrial applications requiring large-part or high-volume injection molding.
The right injection molding company depends on the technical, regulatory, production, and commercial requirements of the program. Medical-device manufacturers may prioritize ISO 13485 and cleanroom capability, while aerospace and defense programs may require AS9100, traceability, documentation, and tight process control.
OEMs should evaluate suppliers across the full manufacturing lifecycle rather than comparing company size or molded-part price alone.
| Selection Factor | Why It Matters |
|---|---|
| ISO 9001 | Demonstrates a structured quality management system |
| ISO 13485 | Particularly important for medical-device manufacturing |
| AS9100 | Important for aerospace and defense supply chains |
| Cleanroom Manufacturing | Supports contamination-sensitive medical, pharmaceutical, and electronics applications |
| Engineering & DFM | Helps identify manufacturing problems before tooling is built |
| Mold Flow Analysis | Can help optimize filling, cooling, gate locations, and molding risks |
| In-House / Managed Tooling | Simplifies mold development, modification, maintenance, and production coordination |
| Engineering-Grade Resin Experience | Important for demanding thermal, chemical, dimensional, and structural requirements |
| Secondary Operations | Can reduce the number of outside suppliers required |
| Assembly | Allows the molder to deliver higher-level finished products |
| Multiple Molding Technologies | Provides more manufacturing options as product requirements evolve |
| Prototype-to-Production Support | Allows one supplier to support a program throughout its lifecycle |
For buyers comparing those factors, Hi-Rel Plastics Riverside provides injection molding alongside certified quality systems, engineering support, mold manufacturing, cleanroom production, LSR molding, secondary operations, and assembly.
Request a Quote if you want Hi-Rel to review your drawings, tooling, material requirements, expected annual quantities, or production needs.
California has many capable injection molding companies, and no single manufacturer is the right fit for every application. Hi-Rel’s advantage is the ability to support a broad range of quality-sensitive plastics programs within one manufacturing relationship.
Hi-Rel operates under:
ISO 9001:2015
ISO 13485:2016
AS9100 Rev D
This combination supports quality-sensitive programs across medical, aerospace, defense, industrial, electronics, automotive, and other markets.
Hi-Rel’s manufacturing capabilities extend beyond thermoplastic injection molding to LSR molding, blow molding, thermoforming/vacuum forming, rotational molding, mold manufacturing, prototyping, secondary operations, and assembly.
For OEMs with multiple plastic components or processes, consolidating work with a broader supplier can simplify purchasing, engineering communication, tooling coordination, and supply-chain management.
Hi-Rel supports advanced engineering and high-performance materials used for demanding applications, including PEEK, ULTEM/PEI, PPS, PPSU, PES, PVDF, LCP, PBT, glass-filled nylon, polycarbonate, and other specialty thermoplastics.
This experience can be relevant to applications requiring elevated temperature resistance, strength, dimensional stability, chemical resistance, or other demanding material properties.
Hi-Rel combines ISO 13485 certification with cleanroom injection molding and assembly capabilities for medical devices, diagnostics, laboratory products, and other contamination-sensitive components.
OEMs developing regulated products can also review Hi-Rel’s dedicated medical device injection molding capabilities.
AS9100 Rev D certification supports programs that require rigorous documentation, quality management, traceability, and process control for aerospace and defense supply chains.
Hi-Rel can support multiple stages of a plastics program:
Concept → DFM → Mold Flow Analysis → Prototype → Mold Manufacturing → Injection Molding → Inspection → Secondary Operations → Assembly → Packaging → Production
For purchasing and engineering teams, this type of vertically integrated approach can reduce the coordination burden associated with managing separate engineering, tooling, molding, finishing, and assembly suppliers.
Rather than searching only for the largest injection molding company in California or the lowest quoted piece price, buyers should qualify suppliers according to the actual requirements of the program.
Before requesting a quote, consider providing potential manufacturers with:
Providing this information allows injection molders to evaluate tooling, equipment requirements, materials, cycle time, automation, quality requirements, and secondary operations more accurately.
For projects where certified quality systems, tooling, cleanroom manufacturing, specialty materials, secondary operations, or multiple plastics processes are important, Hi-Rel Plastics Riverside can review the complete manufacturing requirement rather than only the molding step.
If your company is evaluating plastic injection molding companies in California, Hi-Rel Plastics & Molding Corp. can review your project from initial design through production.
With 40+ years of plastics manufacturing experience, a Riverside, California manufacturing operation, and ISO 9001:2015, ISO 13485:2016, and AS9100 Rev D quality systems, Hi-Rel supports customers throughout Southern California, Northern California, and across the United States.
Whether your project requires a precision injection molded component or a broader manufacturing program involving engineering, mold manufacturing, injection molding, LSR molding, cleanroom manufacturing, blow molding, secondary operations, assembly, and packaging, Hi-Rel can evaluate the requirements and develop a manufacturing approach around the program.
Request a Quote from Hi-Rel Plastics & Molding Corp.
Hi-Rel combines 40+ years of plastics manufacturing experience with ISO 9001:2015, ISO 13485:2016, and AS9100 Rev D quality systems. Its capabilities include injection molding, tooling, cleanroom manufacturing, LSR molding, engineering support, secondary operations, assembly, and other plastics manufacturing processes.
Hi-Rel provides custom and precision injection molding, tight-tolerance molding, insert molding, overmolding, LSR molding, engineering-grade thermoplastic molding, cleanroom molding, engineering and DFM support, mold manufacturing, secondary operations, assembly, and packaging support.
Yes. Hi-Rel supports medical-device and other quality-sensitive applications under ISO 13485:2016 and provides cleanroom injection molding and assembly capabilities. Buyers can review its medical device injection molding services for additional information.
Hi-Rel operates under AS9100 Rev D as well as ISO 9001:2015 and supports aerospace, defense, and other applications that require structured quality systems, documentation, process control, and precision manufacturing.
Yes. Hi-Rel’s broader plastics manufacturing capabilities include LSR molding, blow molding, thermoforming/vacuum forming, rotational molding, mold and tool manufacturing, prototyping, secondary operations, assembly, and packaging support.
Yes. Hi-Rel can support projects through DFM, mold flow analysis, prototyping, mold design and manufacturing, molding, inspection, secondary operations, assembly, packaging, and ongoing production.
Hi-Rel Plastics & Molding is located at 7575 Jurupa Ave, Riverside, CA 92504. The company supports OEMs throughout Southern California, Northern California, and across the United States.
Buyers should compare required certifications, engineering support, tooling, material expertise, cleanroom capability, production volume, tolerances, inspection requirements, secondary operations, assembly support, and experience with the target industry. The right supplier depends on the specific technical and commercial requirements of the program.
