As a professional manufacturer specializing in zinc oxide (ZnO) varistor disks and silicon carbide (SiC) varistor disks — the core components at the heart of modern surge arrester technology — we deliver world-class components that power the overvoltage protection systems of electrical utilities, renewable energy installations, and industrial infrastructure worldwide.
Our ZnO and SiC varistor disks are engineered to IEC 60099-4, IEEE C62.11, and GB/T 11032 standards, ensuring full compatibility with internationally certified surge arrester designs. With in-house manufacturing, full material control, and comprehensive testing capabilities, we deliver quality, consistency, and supply chain security that global buyers trust.
Why partner with us?
Our R&D team focuses on the micro-structural homogeneity of ZnO grains. By optimizing the sintering profile in our automated tunnel kilns, we achieve a narrower tolerance in voltage gradient and superior aging stability, ensuring your arresters pass the most stringent type tests at KEMA/CESI.
- Full in-house manufacturing from raw material batching to finished disks — complete quality traceability
- Diameter range: 30mm to 138mm (ZnO) / 6mm to 150mm (SiC), with custom thicknesses available
- Certified to IEC 60099-4:2014 and IEEE C62.11 standards
- ISO 9001, ISO 14001, KEMA certified manufacturing facilities with ERP/MES traceability
- Flexible OEM/ODM options with rapid prototyping and competitive lead times
Product Overview
Our varistor disks are the fundamental building blocks of both gapless metal-oxide surge arresters and silicon carbide arresters. Operating on the principle of voltage-dependent nonlinear resistance, these disks present extremely high impedance under normal operating voltage (leakage current in the microamp range) and transition to a highly conductive path within nanoseconds when a transient overvoltage occurs, safely diverting surge current to ground and clamping the voltage to a safe level.
For ZnO varistors, each ZnO grain contributes approximately 4V of switching voltage; the overall varistor voltage is achieved by connecting these grains in series through the sintering process. For SiC varistors, the nonlinear characteristics are derived from the grain boundary barrier effect of sintered SiC particles doped with ceramic binders and dopants such as nitrogen or phosphorus.
We manufacture both technologies to provide our customers with comprehensive sourcing solutions for different application requirements, product tiers, and regional market preferences.
Product Specifications
Zinc Oxide (ZnO) Varistor Disks
Our ZnO varistor disks are manufactured using high-purity zinc oxide (ZnO > 90 mol%) blended with proprietary metal oxide dopants, pressed into precision dies, and sintered in advanced tunnel kilns under tightly controlled atmospheric conditions to produce a polycrystalline ceramic structure with highly resistive grain boundaries.
| Parameter | Specification Range |
|---|---|
| Diameter | 30mm – 138mm |
| Thickness | 3mm – 40mm |
| Varistor Voltage (U₁mA) | Customizable per customer requirement |
| Leakage Current (0.75 U₁mA) | ≤ 50 μA |
| Residual Voltage Ratio | ≤ 2.0 (at nominal discharge current) |
| High-Current Impulse Withstand (4/10 μs) | Up to 100kA |
| Long-Duration Impulse Withstand (2ms square wave) | Up to 2,000A |
| Energy Absorption Capability | Application-specific, up to high-energy classes |
| Operating Temperature Range | -40°C to +85°C |
| Accelerated Aging (1000h @ 115°C) | U₁mA variation ≤ ±5% |
Custom diameters, thicknesses, and electrical parameters available upon request.
Silicon Carbide (SiC) Varistor Disks — Rods — Tubes
Our SiC varistor products offer high power dissipation and high energy absorption for applications where extreme reliability is essential. The material comprises approximately 90% silicon carbide of controlled grain sizes (typically 0.3–70 μm) with 10% ceramic binder and additives, sintered under specific atmospheric conditions. Standard metallized contacts include brass (flame-sprayed), aluminum, copper, and silver.
| Product Type | Dimensions | Key Specifications |
|---|---|---|
| Disks | OD: 40mm – 150mm; Thickness: 2mm – 25mm | Energy absorption: up to 122,290J per disk; operating temp: -40°C to 150°C; TCV: -0.12% to 0.18%/°C |
| Rods | OD: 6mm – 30mm; Length: up to 600mm | Ohmic range: 500 – 17×10⁶ Ω/cm; max pulse residual voltage: 4.3×1.2√(log(R×A×l)) kV/cm; essentially zero inductance |
| Tubes | OD: 6mm – 30mm; ID: up to 8mm; Length: up to 600mm | Same electrical parameters as rods; density: 1.9–2.0 g/cm³ |
SiC disks can be configured in series and parallel stacks to achieve energy absorption ratings in the tens of Mega-Joules, making them ideal for generator field discharge, magnet coil protection, and high-energy industrial applications.
Certification and Compliance
All our varistor products are manufactured and tested in accordance with internationally recognized standards:
We are prepared to provide complete test reports and third-party certification documentation, including third-party lab verification (KEMA/CESI accredited upon request), supporting your market access requirements in Europe, North America, and other regions.
Testing Capabilities
Our in-house testing laboratory is equipped to perform all routine and type-testing procedures required by international standards, including:
Our manufacturing process is governed by a 6S management system, with every product batch traceable through our ERP and MES systems from raw material sourcing to final testing, ensuring full visibility and accountability at every stage of production.
Why Source Varistor Disks from Our Facility
Complete Process Control
Unlike many surge arrester manufacturers who outsource varistor production, we manufacture our disks entirely in-house. From raw ZnO and SiC material selection through mixing, granulation, pressing, sintering, electrode application, and final electrical testing, every step is under our direct control. This vertical integration means consistent quality, faster response times, and true customization capability.
Advanced Production Equipment
Our manufacturing facility features advanced Japanese spray granulation towers, horizontal double-faced grinding machines, large double-push tunnel kilns, automated aluminum spraying equipment, and dedicated varistor aging test systems — enabling precision manufacturing at scale.
Engineering Support
Our team of material scientists and electrical engineers provides full technical support, including:
- Application engineering: Selection of varistor voltage classes, diameter, and thickness based on arrester design specifications
- Stack assembly optimization: Guidance on series/parallel configurations for required voltage and energy ratings
- Custom formulation: Tailored dopant packages for specific nonlinearity coefficients or aging characteristics
Global Supply Chain Experience
With years of export experience to North America, South America, Europe, Southeast Asia, Africa, the Middle East, and Eastern Asia, we understand the documentation, logistics, and compliance requirements of international buyers. Our trade terms include FOB, EXW, CFR, CIF, and CPT, with flexible payment options including L/C and T/T.
Market Context: Growing Global Demand for Varistors
The global Metal Oxide Varistor market was valued at USD 13.30 billion in 2025 and is projected to reach USD 26.38 billion by 2032, representing a CAGR of 10.27%. This growth is driven by:
- Renewable energy expansion: Solar and wind installations require robust surge protection for inverters, transformers, and grid interconnection points
- Electric vehicle infrastructure: High-voltage fast-charging stations create significant transient stresses that demand high-performance varistors
- Smart grid modernization: Global grid spending is projected to reach USD 400 billion in 2024, driving demand for station-class surge arresters
- Telecommunications and 5G: Network infrastructure requires high-density, reliable overvoltage protection at every node
As a varistor disk manufacturer at the upstream of this supply chain, we are strategically positioned to support arrester manufacturers worldwide in capturing these growing market opportunities.
We are also providing brackets, disconnectors, discharge counters to our customers from the world. Many surge arresters factories have increased their products quality and reduce the production costs when they purchased the varistor blocks, brackets, disconnectors and discharge counters from us.
We, a professional supplier, not only offer qualified products but also provide solutions for the cost reduction and efficiency improvements. If you are a surge arrester factory, our products will be good for you.
Contact Us for Inquiry
To request technical datasheets, sample disks, or a quotation, please contact us with your specific requirements, including:
- Target varistor voltage (U₁mA) and classification
- Required disk diameter and thickness
- Nominal discharge current (8/20 μs) and high-current impulse (4/10 μs) requirements
- Annual volume projection
