Have you ever noticed that the left brake latch is magnetized on many two-cylinder tractors that have the batteries under the seat? It can be quite noticeable when you hold the latch close to the pedal. How does this happen?
Let’s face it, no one really knows how magnets work. Okay, maybe some really smart people do, but for the rest of us, let’s remember when we were kids and we wound a length of copper wire around a nail and hooked the ends to a battery to create an electro-magnet. It’s the same sort of thing on the two-cylinder tractor with the battery cable passing near the brake latch, except it happens much more gradually and the metal eventually becomes magnetized. Why just the brake latch? Perhaps because it is the metal object in the area with the least mass, therefore the easiest to magnetize. It is also in a linear position next to the cable, and a shape that is similar to the bar magnets we are all familiar with. And the brake latch was also manufactured from good quality medium carbon steel to resist wear without getting brittle. In general, the better the steel, the better a magnet it makes.
