Steel Nylon-Insert Lock Nut 5

ISO 898-2 class 5 nylon-insert prevailing-torque lock nuts to DIN 985 / ISO 10511 (often called Nyloc). A polyamide ring in the crown deforms onto the bolt thread and resists rotation after tightening. Metric coarse, listed M3–M39. Pair with class 4.8 bolts.

Use on light machinery, guards, enclosures, and assemblies that see vibration but modest preload. The insert is a polymer: typical service is well below ~120 °C, and these nuts are not for fire-rated or oven-cured joints — choose an all-metal DIN 980 lock nut there. Prevailing torque drops with reuse; treat them as limited-reuse. Do not combine with a spring washer as a substitute for a proper lock nut.

Select metric sizes above. Quote with quantity, coating, and destination; matching 4.8 bolts and flat washers can go in the same enquiry.