The 5’s staple bolt nut was finally removed today. One face had already been sawn off, and filed down until the bolt’s threads started to show through. Today the remaining strips of the nut’s threads on that side were partially drilled out, after each one was dimpled with a center punch to keep the drill bit in the metal of the nut. Then the opposite face was sawn off and filed down to the same level. Penetrating oil was applied yet again, then the sawn face was struck off-center with an engineer’s hammer and a drift punch to try to stretch the nut and turn it, first in one direction then the other. With so much metal removed on the two sides, the nut stretched enough to break the rust, and it started to turn. After the nut was hammered back and forth several times with more penetrating oil, an adjustable wrench was tightened on the sawn faces and the remains of the nut could be turned off the bolt.
The threads of the staple bolt were oiled and wire-brushed at length to clean the rust out, and wiped until rust stopped coming off onto the rags. Then the threads were greased with molybdenum disulphide paste, and the nuts (the original lock nut and a new nut) were spun up and down the threads until the paste covered all the threads and the nuts spun smoothly.