hey guys.. i bought this really good set of scalpel type knives from a dollar store the other day. it was 3 handle sizes (big ass screw driver style, medium and fine pen style). there is also a large variety of interchangable blades to attach. on of them is a flat blade. this blade, whilst i don't know the real purpose, does not cut. when i tried it on a scrap peice of paper, i found that it is a EXCELLENT scoring tool. i haven't tried all the blades but what are the differences between the shapes of the blade? :???: also, what am i supposed to use the screwdriver handle for?