Ductile Iron Cover and Frame

Our Dingjian brand Ductile Iron Cover and Frame is a reliable solution for city roads and heavy traffic areas. This round three-proof manhole cover meets the D400 load rating and can safely handle 400 kN of pressure. It remains stable under heavy traffic and large trucks. It helps prevent sinking, cracking, and deformation during long-term use.

The standard size is 700 mm in diameter, with overall dimensions of 380 mm × 680 mm. This size is suitable for many municipal road projects and urban infrastructure applications.

The ductile iron cover and frame work as a complete set. We manufacture the cover and frame together to ensure accurate matching and stable installation. The tight fit helps reduce noise when vehicles pass over the manhole cover.

The three-proof design provides effective protection against theft, unwanted movement, and settlement. These features solve common problems found in road manhole applications. The ductile iron material provides excellent strength and flexibility. It can withstand heavy loads, impact forces, and temperature changes while maintaining reliable performance.

Our factory, Changxing Jianguo Ductile Iron Manhole Cover Factory, has 24 years of manufacturing experience. We operate a complete production line covering melting, casting, processing, and finished product inspection.

We follow the ISO 9001 quality management system. For each D400 ductile iron cover and frame, we perform strict quality control procedures. We test the molten iron before casting, inspect the material after treatment, and verify the final load capacity of finished products.

Every production step follows national standards. This product is ideal for city main roads, municipal engineering projects, and large infrastructure applications. It provides a dependable solution for long-term road safety.