[rotorwrench]

MS21042 and MS21043 nuts are used a lot in aviation but they are generally a nut that needs to be replaced when the drag torque becomes too low. They are used a lot on turbine engines in their stainless steel form since most of the screw/bolts are also stainless. They use a lot of small ones closely spaced to hold the turbine and compressor sections together. I don't know if I'd want to use them inside an engine or not. They are pretty strong but they are also pretty thin in cross section.

Those MS20500 nuts in the link on post #15 are a Marsden type that are also silver plated for heat corrosion resistance. There is an MS21045 nut that is the same design but in steel with type II Cad plate. All of the above are tension nuts rated at 125KSI tensile strength. The thin nylock types are made for shear. The don't have a lot of tension strength. The thick nylocks do and are tension types but keep in mind that the nylock material takes up a good bit of room for metal threads.