Established on July 22, 2015, Shandong Jinhao Electrical Technology Co., Ltd. is headquartered in Bancheng Town, Lanshan District, Linyi City, Shandong Province.
The company occupies a 30‑acre production base, with a workforce of over 200 employees, including 50 dedicated management and technical professionals. We operate highly intelligent production lines and fully automated cementing assembly lines, supported by comprehensive, technologically advanced chemical and electrical testing laboratories. Our well‑equipped finished goods and semi‑finished goods warehouses ensure stable, efficient production processes and strict, reliable quality control.
Focused on the ultra‑high voltage (UHV) power transmission industry, Jinhao Electrical specializes in the R&D and manufacturing of power system glass insulators. Our flagship products include toughened glass disc suspension insulators and precision power fittings, widely applied in UHV transmission and distribution projects.
In recognition of our innovation and capabilities, the company has been awarded prestigious titles including National High‑tech Enterprise and Science and Technology Small & Medium‑sized Enterprise.
Modern Management System
Shandong Jinhao Electrical Technology has established a modern, standardized group management system structured around five core functional departments to ensure efficient operations and strategic coordination:
- R&D Center
- Manufacturing Center
- Marketing Center
- Quality Management Center
- Administrative & Financial Center
R&D & Innovation Leadership
- Continuous R&D Investment: We allocate no less than 5% of annual sales revenue to research and development, ensuring sustained technological edge in the power insulator industry.
- Patent Portfolio: The company holds 1 national invention patent and 4 utility model patents, reflecting our commitment to innovative product development.
- Comprehensive Certifications: We have successfully passed authoritative management system certifications:
- ISO9001 (Quality Management System)
- ISO14001 (Environmental Management System)
- ISO45001 (Occupational Health and Safety Management System)
- ISO20001:2018 (Energy Management System)
- SR10:2015 / ISO26000-2011 (Social Responsibility Management System)
- International Recognition: Selected products have obtained CMA and CNAS international authoritative certifications, validating our global quality standards.
Comprehensive Product Range
Our product specifications cover a full spectrum of 10kV to 800kV voltage levels, meeting the diverse application requirements of transmission lines and power stations for AC, DC, and all lower voltage systems.
Development Vision & Mission
Since its establishment, Jinhao Electrical has consistently taken technological innovation as the core driving force. With exquisite craftsmanship, strict quality control, and reliable product performance, we continuously extend towards the high-end of the industrial chain.
We are committed to becoming a technological and market leader in the global power insulator industry, providing solid technical guarantees for building a clean, safe and intelligent global energy system.
Production Process
The production of toughened glass insulators is a precise, high-temperature process that creates a surface-compressive stress layer for high mechanical strength, electrical insulation, and thermal stability. Below is the full, step-by-step manufacturing flow:
1. Raw Material Preparation & Batching
- Core raw materials: High-purity quartz sand (SiO₂), feldspar, limestone, dolomite, soda ash (Na₂CO₃), and potassium carbonate (K₂CO₃).
- Incoming inspection: Test chemical composition, particle size, and moisture; only qualified materials are used.
- Precise mixing: Weigh and blend in strict ratios using a forced vertical-axis mixer to ensure uniform composition.
- Drying: Quartz sand is dried to avoid moisture-induced defects.
2. Melting & Refining (1500–1600°C)
Mixed batch is fed into a continuous glass furnace and heated to form homogeneous glass liquid:
- Silicate formation: Raw materials react to form silicates.
- Glass formation: Silicates melt into a glassy state.
- Clarification: Remove bubbles (using fining agents) to prevent internal defects.
- Homogenization: Stir to ensure uniform composition.
- Cooling: Adjust temperature to molding viscosity (~1000°C).
3. Press Molding
- Molten glass gob is fed into a precision mold on a rotating press.
- A stamp forms the internal cavity; the mold defines the outer shape (disc, pin-type, etc.).
- Critical: Control glass volume and pressure to ensure uniform wall thickness (minimizes breakage during toughening).
- Temperature: ~1000°C during pressing.
4. Homogenization (Soaking)
Freshly pressed glass shells go through a homogenization furnace to:
- Maintain uniform high temperature (to eliminate residual stress from molding).
- Prepare for uniform toughening cooling.
5. Toughening (Tempering)
Rapid, controlled cooling creates surface compressive stress (the key to high strength):
- Glass is heated to near softening point.
- Air quenching: High-pressure air jets cool the surface quickly; the core cools slowly.
- Result: Surface is in compression (~100–200 MPa), core in tension – gives 4–5× mechanical strength vs. ordinary glass.
6. Thermal Shock Test (Quality Screening)
- Heat shells to ~300°C, then plunge into cold water (temperature drop ~420°C).
- Purpose: Eliminate defective units (those with internal stress or impurities will shatter).
- Surviving pieces proceed; broken glass is recycled as cullet.
7. Metal Fitting Assembly (Cementing)
- Components: Toughened glass disc, hot-dip galvanized steel cap, steel pin, zinc sleeve.
- Bonding: Use high-strength alumina cement to fix cap/pin to the glass.
- Curing: Assembly is cured in a 70°C water bath for ~1 hour to develop cement strength.
8. Final Inspection & Testing
Every finished insulator undergoes strict testing:
- Visual: Check for cracks, bubbles, chips, and bonding defects.
- Electrical: High-voltage withstand, insulation resistance, and partial discharge tests.
- Mechanical: Tensile, bending, and torsion strength tests.
- Environmental: Thermal cycling, pollution resistance, and UV aging tests.
9. Packaging & Storage
Qualified products are packaged with shockproof materials and stored in dry conditions before shipment.
Why Choose Us
We are a professional manufacturer and supplier of high-performance glass insulators for power transmission and distribution systems. Here’s why customers worldwide choose us as their trusted partner:
1. Superior Product Quality
• Manufactured from high-strength tempered glass with excellent mechanical and electrical properties. • Stable insulation performance, anti-aging, anti-corrosion, and weather-resistant for long-term outdoor use. • Strict quality control from raw material to finished product, complying with international standards.
2. Complete Product Range
• Standard Profile Toughened Glass Insulators • Anti-Fog Pronie Tougnened Glass Insulators • Aerodynamic Profile Toughened Glass Insulators • Three-alternating Profile Toughened Glass Insulators • Two-alternating Profile Toughened Glass Insulators
3. Strong Production Capacity
• Advanced automatic production lines with stable output. • Short lead times and reliable delivery schedules. • Ability to support large-scale power grid projects.
4. Competitive & Cost-Effective Pricing
• Factory direct sales with no middlemen. • Stable cost structure offering high cost-performance ratio. • Flexible pricing for bulk orders and long-term partnerships.
5. Professional Technical Support
• Experienced R&D and engineering team. • Customized solutions, installation guidance, and after-sales service. • Full technical documentation and certification support.
6. Reliable After-Sales Service
• Timely response to inquiries and feedback. • Comprehensive warranty and quality assurance. • Long-term partnership-oriented service system.
Second Thermal Shock Test
This test is the Second Thermal Shock Test for glass insulators, which is a key quality verification test following the First Thermal Shock Test. The purpose is to further verify the structural stability and thermal shock resistance of the glass insulator products under repeated temperature changes, screen out products with insufficient tempering stress or internal microcracks, and ensure the long-term reliability of the products in actual operation. The test is carried out in accordance with IEC 60383-1 and GB/T 1001.1 standards.
Client Testimonials
"After an extensive selection process, we chose Shandong Jinhao Electrical Technology Co., Ltd. as our supplier for the 500kV UHV transmission line project. Their tempered glass insulators demonstrated exceptional performance under extreme climate conditions during on-site testing. The consistent quality and compliance with international IEEE standards have made them a trusted partner in our mission to strengthen the national power grid."
nTDC
"Working with Shandong Jinhao Electrical Technology Co., Ltd. has been a game-changer for our procurement team. We have been importing their glass insulators for over three years for projects in Southeast Asia. What impresses us most is their unwavering quality consistency and the reliability of their supply chain. Despite peak season demands, they always meet our tight delivery schedules. Their professional technical support team has also been invaluable in resolving complex customer inquiries."
EDC
"We required a special design of glass insulators to withstand high pollution levels in coastal areas. The R&D team at Shandong Jinhao Electrical Technology Co., Ltd. worked closely with us to develop a customized anti-fouling solution. Their engineering expertise and rapid prototyping ability allowed us to bring the product from concept to approval in record time. We are highly satisfied with the results and the ongoing technical guidance they provide."
EGAT
"During a recent large-scale shipment, we encountered a minor logistics issue. The customer service team at Shandong Jinhao Electrical Technology Co., Ltd. responded immediately and handled the situation with utmost professionalism. They kept us informed throughout the entire process and ensured our project timeline was not affected. Their commitment to customer satisfaction goes beyond just selling a product. We look forward to continuing our partnership for years to come."
kPLC
Trusted By 100 more clients
We are proud to be trusted by over 100 power utilities, engineering contractors and industrial clients across the globe. Our glass insulators deliver consistent quality, reliable performance and long-term safety for transmission and distribution projects.
