how much shrinkage caused when i made screw conveyor form the ms sheet -3mm thick,inner dia-38mm,outer dia of spiral=200mm so please advice me?
It would help if you did not use an abbreviation such as MS sheet as I have no idea what you are asking about. What is the MS? And what type of shrinkage are you asking about, under what conditions?
If you are referring to the developed shape of the auger flight, it is more economic to use continuous rolled flight from someone like this: http://www.pressedflights.co.uk there are a few UK companies who have the necessary machine. As your core tube is light I guess your application is not demanding in which case a rollformed flight will save you days of endless fun!
I assume MS is mild steel and by shrinkage you mean bending K factor (because when you bend sheet it stretches and "shrinks"). K factor is an empirical number that depends on the particular bending tools and procedure. You can guess at it (that is all I could do with the information given), but where very good accuracy is needed it is better to just tweak the setup and assume some scrap getting it right. Sorry. Mike
