Small pack Field of Application: Only suitable for screws of strength class ≤ 5.8. For higher strength classes, Schnorr lock washers (art. no. 0493/0493 0) or Nord-Lock lock washers (art. no. 0435 0) should be used. Advice: Do not use the ring in applications with direct exposure to the weather or in wet rooms with atmospheres containing chlorine gas.