If you wash belts or coins, the door glass might break
Removing belts from your trousers and jeans is HIGHLY mandatory. Even if the glass of the washing machine doors is toughened, a belt buckle spinning at no less than 1,600 rpm would undoubtedly break the glass in the door in an instant.
Even more, something very small such as a coin might end up blocking the filter or even causing a din when your machine spins. Once you’ve removed the belts from the laundry, you should also consider using a laundry bag for any of your clothes that have large metal buttons.
Plus, lowering the spin might help mitigate the already low risk of glass breaking.