1.cast steel bottom frame 2.low carbon or low alloy steel 3.max.:150 tons per unit 4.MT ... dimension test 5.rough or finishe Material:Carbon steel,low alloy steel:ZG20SiMn,ZG50Mn,ZG35SiMn,ZG35CrMo,ZG35SiMnMo,ZG42CrMo,ZG40Cr, ... requirement from customer.Standard&certificate:ASTM,BS,NF,DIN,JIS and so on; ISO 9001:2000;BV,CCS,DNV ... obtain a smooth surface. ex-factory price large cast steel bottom frame