A few things I've picked up over the years in heavy industry, etc.:
- Structural steel is not supposed to feel spongy.
- There is such a thing as load-bearing rust.
- The grease you have a 40 gallon drum of is always for a non-critical piece of equipment that only needs to be greased once a year. The grease you have a single half-empty tube of is the kind you need for half the equipment in the facility. They are NEVER compatible.
- If you ever have to check the manual for the "never-exceed" operating parameters, they're always slightly below the current operating parameters.
- The likelihood of having a particular replacement part on hand is inversely proportional to how critical the part is to the equipment's functionality.
And most importantly:
- Do not, UNDER ANY CIRCUMSTANCES, wash a Navy chief's coffee cup.