Split Lock Washers

A single coil of spring section, split and offset so the two ends sit out of plane, to DIN 127B. Compressed flat under the nut, it stores energy and keeps pushing back as the joint relaxes.

What it does and what it does not

A split washer maintains some tension when a joint settles or thermally cycles, and the sharp cut ends bite into the nut face and the surface below. That resists back-off from mild vibration.

It is not a substitute for a prevailing torque nut. Under sustained or heavy vibration, and in any joint where loosening has real consequences, use a nylon insert lock nut. The split washer is the light-duty answer.

Installation

It goes under the part that turns — under the nut if you tighten the nut, under the head if you tighten the bolt. Tighten until the coil is flat; a split washer that has not closed is doing nothing. And do not stack it with a flat washer against a soft surface, because the bite that makes it work lands on the flat washer instead of the joint.

Material

304 stainless. Outside diameter and section are listed for every size in both unit systems.