I was given a piece of half inch thick steel plate about four inches square, we were still working in imperial measurements. I had to clean up and polish the two faces with a file and then emery cloth. It had to be like a mirro. I'm not sure in what order we did this but the edges had all to be filed square to the faces and polished too. I learnt to use a file!
The next project was to do the same with a piece of flat bar and then fill it with holes of varying sizes and then tap them out to produce threaded holes. I learnt how to drill and tap. Mr Potter was the foreman instructor here, a stickler for discipline.