Cast iron front axle support is an important iron part for lawn tractors and small agricultural machines. The followings are introduction to their materials, production process, main defect problems and casting prices.
Ductile Iron Material
The most suitable cast iron materials for cast iron lawn tractor front axles, should be ductile iron ASTM A536 Class 60-40-18, 65-45-12, 70-50-05, 80-55
Gray cast iron is not suitable for producing these parts because of low tensile strength, barely zero yield strength and elongation.
The suitable production processes of lawn tractor front axle should be sand casting by molding machines, or manual molding processes. Although manual molding sand casting process will cause more sand casting defects, but it also has advantages. Manual molding process could allow the tractor front axles cooled in sand molds for longer time, which will reduce the straightness deformation.
Main Quality Problems and Defects
The common sand castings defects happened on the lawn tractor cast iron front axles includes sand inclusion, inside shrinkage, air holes on surfaces, and straightness deformation.
Because most of front axles are very long, so the cast iron foundries should inspect the castings one by one for the straightness. Otherwise, the center of drilling holes at the two ends will have serous deviation.
Whatever by molding machines or manual molding processes, the molding materials will be green sand, so its casting price will not be high. Normally, the raw casting price per kg should be in the range of 1.52 to 1.67 USD/kg.
The surface painting normally are black electrophoretic coating, which will cause extra painting costs about 0.30 to 0.32 USD/kg.
All these above prices per kg has included the packing costs, but without shipping costs.