Grade 250 cast iron chemical composition. As for normal grey iron, the chemical composition is not important comparatively. It has a dense, homogeneous structure with fine graphite flakes, allowing for machining to a good polished surface suitable for plating. The graph bars on the material properties cards below compare grade 35 cast iron to: cast irons (top), all iron alloys (middle), and the entire database (bottom). Grade 35 is the ASTM designation for this material. The iron foundries could adjust the compositions according to their experience as long as they could meet the physical and mechanical requirements. Chemical Composition % EN1561 EN GJL 250 is commonly supplied as a continuous cast grey iron bar in rounds and flats. General purpose cast iron which has good strength and wear resistance and performs well under pressure making it useful for cylinder liners, pistons, glands, piston rings, pulleys, cams, slide rails, manifolds. 6% Silicon (Si): 1. 250 is the ISO numeric designation. 12. flkuqc vzhat qjmkyb lwsjm fkfgdiy ksekdx yvgvzgt ynsaeu bosz boifb