I need a engineer/desinger who work with metals like steel and iron

I need a desinger who can create certain type of cylindrical stainless steel weights. For reference you can go through the images that I've attached. I need those weights to be compact and combinable. Each of the weights should have a screw on one side and a threaded socket on the other side, so that all those weights can be combined with each other. The base weight will have a clip or a hook so that the weight can be hanged. I'll give more details after i get a designer.