As the cappuccino screw was rusty and licked, I replaced it with a stainless steel screw. I think the winker base is plastic so there is no worry about electric corrosion. I think that genuine products (iron) was about 50 yen per book. I am surprised that it is a packed item, but this price is acceptable.
It may become a stupid hole when removing the screw several times with the maintenance of the thing made of resin. In this case 0.5 mm thick screws are useful. Because it is rural, stainless steel has only a flathead screw, so it is saved. Small amounts are also good.