hi, we want to build a dibble with a drilling head for some project and we have some questions:1.we need 2 kinds of steel:one needs to be very very strong and the other strong with ductility. what kinds of stells we need to use? 2. how can we make analysis in solidworks that show how nut screws on screw?3.is making the product from number of parts and assembly will make it weaker?