I only use Organ needles. I have had a few come loose or fall out, and figured I just had not inserted them fully up the shank of the machine or had not tightened the screw enough. I re-inserted the needle and re-tightened the screw and they worked fine. So I would not automatically assume a needle is defective or not usable without giving it another try. However the Organ needles do have one flat side, and don't think I have ever used one without a flat side. The only time I have ever broken a needle is either when I hit a pin or when I forgot to move the needle position after changing a foot and the needle hit either the pressure foot or the machine metal plate---oops!!!