Galvanized Fender Washer for Fastening

In heavy-duty fastening scenarios such as steel structure construction and solar mounting installation, standard flat washers often lead to common issues like surface indentation, stress concentration, and contact surface damage. To solve these problems, the Galvanized Fender Washer for Fastening from Ningbo Gangtong Zheli Fastener Co., Ltd. is designed with an enlarged outer diameter. This key feature significantly expands the stress-bearing area, evenly distributes bolt preload, reduces the risk of substrate crushing, and effectively improves the long-term stability of the entire connection system.

Backed by 16 years of professional fastener manufacturing experience, our factory guarantees reliable, stable supply. We provide verifiable workshop footage and shipping videos for transparency, and implement standardized quality control throughout every stage of production. This rigorous process ensures consistent dimensional accuracy and stable mechanical properties for every batch of our washers.

Features & Advantages

Galvanized Fender Washer for Fastening developed by Ningbo Gangtong Zheli Fastener Co., Ltd. is designed with an oversized outer diameter, which makes it different from standard washers in how it works. The larger size spreads the bolt’s clamping force over a much wider area of the mounting surface. This simple change brings three key benefits:

First, it prevents the washer from sinking into thin or soft materials like wood, metal sheeting, or composite panels. Second, it protects painted or coated surfaces from damage by reducing concentrated pressure. Third, it improves stability in vibrating environments, helping to keep the bolt tight longer.

For an M12 bolt, this product has an outer diameter of 37 mm. Compared to a standard M12 flat washer, this gives you about 140% more contact area. That means the same bolt load is spread over nearly two and a half times the surface, cutting local pressure by more than 60%. This makes the washer ideal for use in solar panel mounts, steel frames, and outdoor structures where reliability matters most.

Production & Quality Control

Ningbo Gangtong Zheli Fastener Co., Ltd. manufactures the Galvanized Fender Washer for Fastening strictly in accordance with international standards including DIN 9021 and ISO 7093, with key dimensions controlled to GB/T 3098.12 tolerances. For M12: inner diameter 13.00–13.27mm, outer diameter 36.38–37.00mm, thickness 2.7–3.3mm. All dimensions are inspected batch by batch using coordinate measuring machines to ensure compatibility and interchangeability.

• Raw material: high-quality medium carbon steel, carbon content 0.25%–0.55%, balanced hardness and toughness;
• Galvanized coating: ≥8μm, salt spray test 48–96 hours for outdoor corrosion resistance;
• In-house testing laboratory with fully transparent key parameters; each batch is issued with test reports covering hardness, dimensions and proof load for full traceability.

Capacity & Delivery Support

Ningbo Gangtong Zheli Fastener Co., Ltd. runs large-scale production lines with a daily capacity of over 100,000 pieces. Regular sizes are in stock, and we accept custom orders, including customized Galvanized Fender Washer for Fastening. All products are produced and tested in line with international fastener standards, featuring mature craftsmanship and consistent quality. Our factory has long supplied construction and photovoltaic projects across the globe, winning consistent recognition from customers thanks to reliable production capacity and steady delivery.

Applications & Credibility

Galvanized Fender Washer for Fastening by Ningbo Gangtong Zheli Fastener Co., Ltd. is designed for heavy-duty fastening: it reduces stress concentration in steel structure joints, improves wind vibration and slip resistance in solar mounting systems, and protects the base surface from damage during equipment base installation. Tested proof load meets GB/T 3098.2 requirements, with the M12 specification having a minimum proof load of ≥87kN, ensuring no plastic deformation after installation for a longer service life.

As a professional fastener manufacturer, Ningbo Gangtong Zheli Fastener Co., Ltd. relies on 16 years of industry experience, proven technical capabilities through transparent test data, authoritative recognition through real factory and production processes, and long-term trust through verifiable factory addresses, fast after-sales service and flexible customization, providing stable, reliable and traceable fastening solutions for global customers.