If you’re looking to ensure fasteners don’t work their way loose in a high vibration environment, the washers from Nord-Lock are worth considering. The basic premise behind them is to use ramps (at an angle greater than the pitch) to increase the bolt tension as the bolt begins to loosen – and thus ensure that the bolt will not be able to loosen. The video on their website does a good job of explaining this in more detail and comparing it to other popular locking methods.