MS35333-108 | غسالات قفل داخلية بأسنان حسب المواصفات العسكرية | فولاذ (100 / عبوة)

The internal teeth really bit into the bolt head during assembly, and they held tight after I torqued them down on a vibrating pump mount. These are exactly what you need if your fasteners keep backing out.

Installed these lock washers on a small engine mount and they held perfectly through a few hours of heavy vibration. The steel teeth are definitely tougher than the cheap hardware store versions I’ve used before.

Used a handful of these on a bracket that sees a lot of vibration, and they held tight. The steel feels exactly as specified, and the internal teeth bite into the fastener head nicely.