Product Name: Infilled Decorative Ductile Iron Manhole Cover Class B Model NO.: AS3996 Certification: RoHS, ISO 9001:2000 Standard: En124 Surface Roughness: Ra0.05 Surface Treatment: Sand Blast Material: Iron Machining: CNC Machining Application: Municipal Sand Core Type: Clay Sand Core Casting Method: Thermal Gravity Casting Type: Clay Wet Sand Machine: Automatic Machine Trademark: YYTT Transport Package: Packing in Wooden Pallet Specification: ductile iron Origin: Handan HS Code: 73251090 Product Description about ductile iron (Nodular iron)Ductile iron, or nodular iron, obtains its special properties through the addition of magnesium into the alloy. The presence of magnesium causes the graphite to form in a spheroid shape as opposed to the flakes of gray iron. Composition control is very important in the manufacturing process. Small amounts of impurities such as sulfur and oxygen react with the magnesium, affecting the shape of the graphite molecules. Different grades of ductile iron are formed by manipulating the microcrystalline structure around the graphite spheroid. This is achieved through the casting process, or through heat treatment, as a downstream processing step.Product featureNameDuctile manhole coverMaterialDuctile iron GGG50/7, gray ironStandardEN124/1433/1563ClassA15,B125,C250,D400,E600,F900ShapeRound, square, rectangleSize200mm-1200mm or as per customers' drawingSurfaceBituminous blackMoldingDISA Line, Hand ModellingProcessDrawing-mould making-raw casting-sand blasting-rough machining-surface treatment-product inspectionAdvanced technology and equipmentsTensile strength: 500Mpa Yield stress: 320Mpa Elongation rate: 7% Hardness: HBS170-230Load capacityB125 C250 D400 E600 F900ToleranceMachining:+/-0.2mm, finish machining:0.2mmApplicationFootway, car parks, main road, aircraft pavementsAdvantageLongevity corrosion resistance, excellent anti-pressure