Material A) Ductile Iron B) Grey Iron 1) Product information: Manhole covers are manufactured for road construction, ... holes, distortion or any other defects. 2) Material A) Ductile Iron GGG500-7, GGG 400-12, GGG600-3, GGG700-2 B ... ) Grey Iron GG20, 25, 30, 35 3) Designs A) EN124 A15, B125, C250, ... or wood pallet, or as per customers' requirements. cast iron grating