Caterpillar-style premium aftermarket hardened washer. Part reference 6V5841. Size/application: Washer M20. Use with hardware of the identical nominal diameter. Distributes clamping load and protects the joint surface in the matching heavy-equipment assembly. Brand compatibility: Caterpillar and premium aftermarket systems built to the matching Caterpillar specification. Standardized dimensions may also fit other major brands when diameter, thread, length and seat are identical. Confirm inside diameter and washer profile.