Caterpillar-style premium aftermarket nut. Part reference 5I6125. Size/application: Nut M16x1.5. Matching bolt references in this catalog include 4I7538. High-strength replacement hardware for the specified plow, track or structural fastening system. 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 thread and nut-seat style before installation.