... spiral blade,without welding 3.easy to installstainl screw stainless screw blade 35-800mm:1. Product DescriptionContinous cold rolled ... pitch , arbitrary thickness.4. our company have 2 sets of helical blade rolling mill specialized facilty and 1 set ... combine havester,corn threshing machine,feed processing machinery,screw conveyer,cement mechanical equipment,industry and mining machinical equipment ...