Demand for non-metallic enclosures manufacturers has grown steadily as industries move away from traditional metal housings toward corrosion-resistant, lightweight, and electrically non-conductive alternatives. According to recent market research, the global non-metallic enclosures market is projected to continue expanding through 2026, driven by growth in renewable energy, EV infrastructure, water treatment, and industrial automation.
This guide answers a core question: which non-metallic enclosure manufacturers are actually worth sourcing from — and why? Whether you need standard NEMA 4X stock, high-volume OEM supply, or custom-engineered solutions for demanding environments, the right manufacturer makes a significant difference in lead time, compliance, and total cost. This list is built for:
- Electrical engineers and procurement teams evaluating qualified suppliers
- OEM manufacturers sourcing enclosures for product integration
- Industrial contractors and distributors comparing brands and capabilities
- Project managers specifying enclosures for energy, infrastructure, or automation projects
Below, we cover 10 leading manufacturers across the US, Canada, Europe, and Asia — comparing materials, certifications, customization capabilities, and ideal use cases, so you can make a confident sourcing decision. Read on to find the best fit for your application.
List of the Top 10 Non-Metallic Enclosures Manufacturers
| Brand | Headquarters | Primary Material | Best For |
|---|---|---|---|
| 1. Stahlin | Belding, MI, USA | Fiberglass (FRP), Polycarbonate, PVC | Corrosive & outdoor industrial environments |
| 2. Hammond Manufacturing | Guelph, Ontario, Canada | Polycarbonate (PC), ABS | OEM buyers & industrial distributors |
| 3. nVent HOFFMAN | London, UK (global) | Fiberglass, Polycarbonate, ABS, Polyester | Large-scale industrial & hazardous environments |
| 4. Eaton | Dublin, Ireland (global) | Fiberglass (FRP), Polycarbonate | Hazardous locations & heavy industrial |
| 5. Hubbell / Wiegmann | Freeburg, IL, USA | Polycarbonate, ABS | Single-source OEM & MRO procurement |
| 6. EXM Manufacturing | Blainville, Quebec, Canada | Polycarbonate, Fiberglass, Steel | Custom OEM orders & renewable energy |
| 7. Fibox | Glen Burnie, MD, USA | Polycarbonate (PC) | Instrumentation & OEM custom programs |
| 8. Integra Enclosures | Mentor, OH, USA | Polycarbonate (PC) | Built-to-order & communications infrastructure |
| 9. Polycase | Avon, OH, USA | ABS, Polycarbonate (PC) | Small-batch custom & direct-buy electronics |
| 10. CHINYO Technology | Jiangsu, China | SMC, BMC | OEM wholesale, high-flame-resistance & EV/energy |
1. Stahlin
Overview:
Stahlin is the manufacturer behind the world's first electrical fiberglass enclosure, founded as Stahlin Brothers Fibre Works in Belding, Michigan and now operating under Robroy Industries. As a fully vertically integrated, Made-in-USA non-metallic enclosure manufacturer, every component is produced in-house — giving buyers consistent quality and a 10-year product warranty. For OEMs and industrial buyers needing custom solutions, Stahlin's ModRight program supports factory-modified enclosures tailored to specific project requirements, backed by a nationwide distributor network covering all 50 U.S. states.
Established: 1935
Headquarters: Belding, MI, USA
Core Products:
- Fiberglass (FRP) NEMA 4X / 4 / 6P enclosures
- Polycarbonate and PVC enclosures
- Junction boxes, instrument enclosures, wall-mount and freestanding cabinets
- Custom and factory-modified non-metallic enclosures (ModRight program)
- HMI covers and enclosure accessories
Primary Material: Fiberglass (FRP), Polycarbonate, PVC
Certifications: NEMA 4X, NEMA 6P, UL Listed, CSA, IEC IP66, IEC IP68
Best For: Oil & gas, chemical processing, wastewater treatment, solar, agriculture, coastal and corrosive environments
2. Hammond Manufacturing
Overview:
Started in a backyard workshop in Guelph, Ontario in 1917, Hammond Manufacturing has grown into a publicly traded global company (TSX: HMM.A) with manufacturing facilities across Canada, the USA, and Europe. While the company covers a broad range of electrical products, its non-metallic Type 4X enclosure line is a well-established choice among OEM buyers and industrial distributors in North America. Hammond sells through a worldwide network of authorized partners, making its non-metallic enclosures widely stocked and accessible for both standard purchases and modified orders.
Established: 1917
Headquarters: Guelph, Ontario, Canada
Core Products:
- Non-metallic Type 4X enclosures (polycarbonate)
- Industrial and electronic enclosures
- Equipment racks and cabinets
- Climate control and power distribution products
Primary Material: Polycarbonate (PC), ABS
Certifications: NEMA 4X, UL Listed, CSA, CE
Best For: OEM manufacturers, industrial automation, telecommunications, electronics
3. nVent HOFFMAN
Overview:
With a portfolio history stretching back over 75 years and a global distributor network of 3,000+ partners, nVent HOFFMAN is one of the most widely specified enclosure brands in industrial electrical engineering. Its non-metallic line covers ABS, polyester, polycarbonate, and fiberglass options — giving buyers flexibility across different environmental demands. The brand's Express Customization service can deliver modified enclosures in as little as 5–10 working days, which is a significant lead time advantage for contractors and OEM suppliers with tight project schedules.
Established: 1922 (as Eldon Enclosures; rebranded under nVent 2019)
Headquarters: London, UK (nVent global); distributed globally
Core Products:
- Non-metallic wall-mount and freestanding enclosures (fiberglass, PC, ABS)
- Junction and terminal boxes
- Modular enclosure systems
- Climate control and cable management solutions
Primary Material: Fiberglass, Polycarbonate, ABS, Polyester
Certifications: NEMA 4X, UL, CSA, IEC, CE
Best For: Petroleum, chemical processing, water/wastewater, telecommunications, marine environments
4. Eaton
Overview:
Eaton is a Fortune 500 power management company with over 100 years of manufacturing history, and its non-metallic enclosures fall under the Crouse-Hinds series — a product line purpose-built for harsh, hazardous, and corrosive environments. For buyers sourcing non-metallic enclosures for classified locations or heavy industrial facilities, Eaton's combination of global engineering support, extensive certifications, and engineered-to-order customization services makes it a strong choice when standard catalog products won't meet spec.
Established: 1911
Headquarters: Dublin, Ireland (global HQ); US operations based in various locations
Core Products:
- Crouse-Hinds series non-metallic enclosures (hazardous and standard)
- B-Line series non-metallic cable trays and enclosures
- Engineered-to-order custom enclosure solutions
- Electrical infrastructure for industrial and energy markets
Primary Material: Fiberglass (FRP), Polycarbonate
Certifications: NEMA 4X, UL Listed, CSA, IEC, ATEX (hazardous locations)
Best For: Hazardous locations, oil & gas, petrochemical, water/wastewater, heavy industrial
5. Hubbell / Wiegmann
Overview:
E.M. Wiegmann & Co. was founded in 1928 in Freeburg, Illinois, and today operates as a Hubbell subsidiary with one of the most complete commercial and industrial enclosure packages in North America — over 7,000 stocked products across NEMA, JIC, non-metallic, stainless, aluminum, and wireway lines. For industrial buyers and OEM manufacturers who need a reliable single-source supplier across multiple enclosure types, Wiegmann's automated manufacturing plant and broad non-metallic selection make it a practical choice with strong distributor availability.
Established: 1928 (E.M. Wiegmann & Co.); acquired by Hubbell 1994
Headquarters: Freeburg, IL, USA
Core Products:
- Non-metallic NEMA 4X wall-mount enclosures
- Small and compact non-metallic enclosures
- Carbon steel, stainless steel, and aluminum enclosures
- Wireway systems and climate control
Primary Material: Polycarbonate, ABS
Certifications: NEMA 4X, UL Listed, CSA
Best For: OEM, commercial construction, MRO markets, multi-material sourcing
6. EXM Manufacturing
Overview:
Founded in 1975 in Quebec by Maurizio Ciocca — continuing a family manufacturing tradition dating back to Milan in 1912 — EXM has grown from a single Canadian factory into a manufacturer with operations in Canada, the USA, and China. Every part of an EXM enclosure is designed, developed, and manufactured in-house, and the company's proprietary BOXCAD online configurator lets buyers design and order custom enclosures directly. With over 29,000 standard products and ISO 9001:2015 certification, EXM serves automation, renewable energy, oil and gas, and food and beverage industries across North America and beyond.
Established: 1975
Headquarters: Blainville, Quebec, Canada
Core Products:
- Non-metallic wall-mount and freestanding enclosures
- Pull boxes and modular enclosure systems
- Custom enclosures via BOXCAD configurator
- Climate control systems
Primary Material: Polycarbonate, Fiberglass, Steel (multi-material)
Certifications: NEMA 4X, UL, CSA, ISO 9001:2015
Best For: Automation, renewable energy, oil & gas, food & beverage, custom OEM orders
7. Fibox
Overview:
Rooted in Finland, Fibox traces its origins to 1966 when it pioneered the injection molding of polycarbonate for electrical applications — making it the architect of the world's first modular polycarbonate enclosure. Today, Fibox USA operates out of Glen Burnie, Maryland, offering over 1,000 standard non-metallic enclosure configurations with UL and cUL listings. The company's in-house customization center handles field modifications and production-volume tailoring, making it a practical partner for both individual buyers and OEM manufacturers who need fast, certified non-metallic enclosure solutions.
Established: 1966 (Finland); Fibox USA established 1997
Headquarters: Glen Burnie, MD, USA (North American operations)
Core Products:
- NEMA 4X / 6P polycarbonate enclosures (ARCA, MNX, CAB series)
- Waterproof and weatherproof industrial enclosures
- Large-format polycarbonate cabinets (up to 32"x24")
- Custom-modified enclosures (in-house customization center)
Primary Material: Polycarbonate (PC)
Certifications: NEMA 4X, NEMA 6P, UL Listed, cUL Listed, IEC IP67
Best For: Instrumentation, process control, automation, harsh outdoor environments, OEM custom programs
8. Integra Enclosures
Overview:
Integra Enclosures bills itself as America's largest manufacturer of polycarbonate enclosures, operating out of a 50,000-square-foot facility in Mentor, Ohio. Nearly all enclosures are built to order, with in-house customization covering machining, printing, and accessory installation — all produced under the same roof. The company's patented Panel Suspension System, which allows infinite range of panel motion within the enclosure, is a design feature not found at most competing suppliers. Integra has made the Inc. 5000 list multiple times, reflecting consistent growth driven by communication, alternative energy, oil and gas, and wastewater customers.
Established: 2000
Headquarters: Mentor, OH, USA
Core Products:
- NEMA-rated polycarbonate enclosures (built to order)
- Custom-machined and printed non-metallic enclosures
- Enclosures with patented Panel Suspension System
- Stainless steel enclosures (via sister brand StrongBox)
Primary Material: Polycarbonate (PC)
Certifications: NEMA 4X, UL Listed
Best For: Communications, alternative energy, oil & gas, water treatment, remote monitoring systems
9. Polycase
Overview:
Polycase has been manufacturing plastic electronic enclosures in Avon, Ohio since 1990, with over 97% of its products made in the USA. Rather than operating through a traditional distributor network, Polycase sells direct to end users — which means buyers get factory pricing without the middleman. The catalog spans 2,100+ enclosure styles from compact potting boxes to NEMA-rated industrial junction boxes, with same-day shipping on in-stock orders and in-house CNC machining and digital printing for custom orders that require no minimum quantity.
Established: 1990 (as Polycase; parent ECP Corporation est. 1951)
Headquarters: Avon, OH, USA
Core Products:
- Plastic NEMA 4X junction boxes and enclosures
- ABS and polycarbonate electronic enclosures (2,100+ styles)
- Waterproof and IP-rated enclosures
- CNC-machined and custom-printed enclosures (no minimum order)
Primary Material: ABS, Polycarbonate (PC)
Certifications: NEMA 4X, UL Listed, RoHS & REACH Compliant
Best For: Electronics, medical devices, telecommunications, prototyping, small-batch custom orders
10. CHINYO Technology
Overview:
Founded in 2011 as Jiangsu Chinyo Technology Co., Ltd., CHINYO stands apart from most non-metallic enclosure companies by operating at the material level: the company formulates its own SMC and BMC compounds, designs molds in-house, and handles precision molding through high-volume production lines — all under one roof. This end-to-end capability makes CHINYO a direct manufacturing partner for OEMs and industrial buyers who require enclosures with higher flame resistance (UL94 V-0), elevated operating temperatures, or superior arc resistance than standard polycarbonate or fiberglass products can deliver. Its non-metallic enclosures are deployed across electrical substations, energy storage systems, EV charging infrastructure, and public transportation, with clients across 15+ countries.
Established: 2011
Headquarters: Jiangsu, China
Core Products:
- SMC / BMC non-metallic electrical enclosures and junction boxes
- Substation enclosures and switchgear housings
- EV charging station enclosures and battery housings
- Custom composite molded enclosures (OEM programs)
Primary Material: SMC (Sheet Molding Compound), BMC (Bulk Molding Compound)
Certifications: UL94 V-0, IEC 60439-1, ISO 9001
Best For: High-temperature and high-flame-resistance applications, electrical infrastructure, energy storage, EV charging, OEM wholesale and custom manufacturing
Conclusion
The non-metallic enclosures market is far from one-size-fits-all. From Stahlin's fiberglass heritage to Fibox's polycarbonate precision and Integra's build-to-order model, each manufacturer on this list brings a distinct strength — whether that's material expertise, customization capability, certification coverage, or distribution reach. The right choice ultimately depends on your application environment, compliance requirements, and sourcing priorities.
For buyers who need to go beyond standard polycarbonate or fiberglass — particularly for high-temperature, high-flame-resistance, or structurally demanding applications — SMC and BMC composite enclosures represent a category that most of the brands above simply don't address. That's where CHINYO Technology stands out. As a China-based manufacturer with end-to-end SMC/BMC capability — from material formulation to mold design and high-volume molding — CHINYO serves OEMs and industrial buyers across 15+ countries who require certified, customizable non-metallic enclosures built to more demanding specifications.
Choosing the right non-metallic enclosure manufacturer is as much about understanding your technical requirements as it is about finding a reliable long-term supplier. We hope this guide gives you a clearer picture of what's available in the global market. If you're evaluating SMC or BMC enclosure solutions for your next project, visit CHINYO's website to explore product options or request a sample.
