Wm. F. McGraw & Co. in Riverview, MI, offers electrical insulation products for switchgear applications that perform. Our engineered composites are designed for demanding electrical heavy-duty applications where it is critical to maintain thermal load, dielectric strength, and dimensions that matter. Our engineered products are performance-based, which enables you to build or upgrade switchgear panels that perform and reliability improves from the inside out
Reliable switchgear materials are more than electrical components; they want materials that will maintain the structural integrity and protect against online thermal, mechanical, or electrical stresses. High dielectric strength composites can increase the safety factor against arc flash and flashover while holding their dimensional accuracy, while having complex geometries. Fire-retardant choices improve fire safety inside closed cabinets. Our materials will neither warp nor degrade from high temperatures and will maintain mechanical stability even in high vibration, load-bearing applications over extended durations. The right selection not only contributes to the longevity of equipment but will improves uptime and operator safety. In systems with only one mistake leading to a costly and unacceptable failure and little room for error, engineered materials matter.
We make each component to specification with the appropriate arc-resistant material chosen for the thermal and electrical conditions of an application. Whether it’s a single part component or a more complex assembly, our manufacturing team will accomplish the design and consistently why in tight tolerances. We produce custom-fabricated parts for switchgear applications:
Insulating Spacers & Standoffs
Insulating spacers and standoffs provide physical clearance between electrically energized components, mitigating any opportunities for arcing or shorted circuits. High-dielectric material provides structural rigidity and electrical insulation over operating voltage ranges.
Bushing Sleeves & Supports Tubes
Bushing support tubes and sleeves for high voltages are installed for two reasons: to lead a conductor through a grounded enclosure, as well as to shield a conductor. The dielectric properties of a bushing sleeve protect against breakdown, while also giving mechanical protection, and multi-dimensional location fix.
Arc Barriers & Shields
Arc barriers and shields are essential elements in preventing flashover and propagation of arcs. Arc barriers and shields can isolate an arc event and dissipate energy away from sensitive switchgear components. These barriers are made with flame-retardant and heat-resistant materials to add even further safety to the system.
Custom Fabricated Panels
Our custom-fabricated panels match the application’s specific needs to act as a mounting surface, cover, or structural insulator. The panels are machined to the specified tolerances to integrate with existing switchgear systems, ensuring safe operations and longevity.
We maintain a wide inventory of high-performance composite materials to support fast turnaround for switchgear manufacturing. Each material form can be custom-cut, turned, or milled to meet unique dimensional and performance criteria. From prototyping to full production, our inventory of rods, tubes, and sheets supports high-quality outcomes tailored to switchgear environments, to match your print or design. We process both flame-rated and thermally stable grades suited for elevated voltage and temperature applications in switchgear environments. Material options are available in:
Rods: These solid cylindrical forms are perfect for applications requiring high compressive strength and electrical insulation. They’re often machined into standoffs, spacers, or turned parts that must endure mechanical load while isolating high-voltage elements. Their rigidity and uniform dielectric properties make them dependable in environments that demand structural integrity and electrical protection.
Tubes: With a hollow center, tubes serve as the go-to material for bushing insulators, conductor guides, and structural isolators. The shape allows for internal clearance while providing exceptional mechanical strength and dielectric reliability. These are essential where protection and separation of conductors from grounded enclosures is critical to performance and safety.
Sheets: Sheets provide the most versatility in fabrication. They are machined into custom panels, arc shields, and enclosures, offering both flame retardancy and excellent thermal resistance. Whether used as internal barriers or structural panels, sheet materials can be precisely cut to meet exact system requirements, making them indispensable for complex assemblies.
We support both air-insulated and gas-insulated switchgear systems with material solutions that balance weight, strength, and safety. We serve OEMs and fabricators across all voltage classes of switchgear. Our materials are tailored to the specific dielectric, thermal, and dimensional needs of each system:
Low-voltage switchgear: These systems require materials that are compact yet durable, capable of fitting into limited spaces without compromising on performance. Components like breakers, busbars, and compact enclosures benefit from flame-resistant composites that maintain structural integrity while providing electrical insulation. Precision tolerances are essential to ensure compatibility with dense assemblies in confined enclosures.
Medium voltage switchgear: Operating at higher voltages introduces greater arc suppression and thermal management challenges. Materials must withstand elevated temperatures and arc energies. Reinforced laminates and structural composites are used to fabricate arc plates, barriers, and mounting systems, providing both mechanical support and electrical insulation while mitigating the risk of fault currents.
High voltage switchgear: These systems demand the highest levels of dielectric strength and environmental resilience. Materials must provide excellent electrical isolation, handle significant voltage gradients, and maintain performance in outdoor or high-load environments. Components are exposed to mechanical stress, vibration, and extreme temperatures, requiring composites that resist aging and perform consistently across extended operational lifespans.
At Wm. F. McGraw & Co., we understand that delivering superior switchgear solutions begins with more than premium materials—it requires end-to-end craftsmanship and engineering insight. From our Riverview MI facility, we provide full-spectrum custom fabrication capabilities tailored for electrical insulation and switchgear system integration.
Our shop is equipped with advanced CNC machinery and high-precision cutting tools:
We partner with your engineering team to co-develop or refine designs for switchgear applications, ensuring optimal function, cost-efficiency, and manufacturability. From reverse engineering obsolete components to launching next-gen systems, we support your innovation with decades of hands-on fabrication experience.
What sets us apart isn’t just the quality of our materials—it’s the depth of our commitment to your success at every phase of production. At Wm. F. McGraw & Co., we bring over four decades of real-world experience and a reputation built on trust, responsiveness, and results.
Our knowledge of switchgear environments means we anticipate your needs before they become problems. Whether you’re outfitting a new panel or replacing aging infrastructure, we bring speed, precision, and a partner’s mindset to every order.
Let’s talk about your project. Whether you need custom switchgear parts, replacement insulation panels, or design consultation for your next assembly, we’re ready to help. Contact Wm. F. McGraw & Co. in Riverview MI to request a quote or schedule a discovery call today.
© 2026Website Powered by Growth Marketing Media
