The idler e lahleloa ka alkali phenolic resin sand kapa sodium silicate-bonded san process.Surface hardness fihla bonyane HRC48-58 le boima ba botebo pakeng tsa 4-6mm(HRC45), ka mor'a hore mocheso phekolo process.Idler e khona ho mamella tšusumetso e phahameng le ho roala ho hanyetsa tlasa maemo a thata a ho sebetsa.