>>111625>>111625>5160 is tougher than 1095 meaning it will flex more without snapping.Depends what you're meaning by saying "tough".
Some metals flex easily and thus hardly break, some won't flex as easily but may break more easily. A "tough" metal usually is one that doesn't flex, also said to be "hard", while one that flexes is one that is said to be "soft", or "springy".
Talking about spring is delicate, because it depends on what kind of strengths we're talking about. If we're talking about trucks, then yeah 5160 is used, but not because it flexes easily, but actually because it hardly flexes and keeps its shape, thus allowing a spring effect to be created. If 1095 was used, the leaf spring would simply deform without returning to its shape, and thus wouldn't provide a spring effect. That's why a leaf spring is made of several thin layers, hence its name, so 5160 can be flexible enough, but won't deform and thus will be durable.
Hardness is defined mostly by the hardening process, but won't go out of bounds of what is allowed by the metal. You can't make it as hard as diamond, or then, it'd be diamond. And 5160 can be much harder than 1095, because that's how it is, it contains chromium, and chromium is hard.
The longer it is, the easier it is to bend it; that's why 5160 is a good metal for knives, because it won't bend. And honestly, breaking it would be kinda hard. I know I myself stuck my RD9 in a tree to climb on it. Not to mention using it as a pry bar. You can't do that with a leafy metal.
But then, it won't hold an edge aswell, because the edge will break when that of 1095 will bend.
Pic related, you can see the difference between a steel containing chromium, on top, and one that doesn't, on the bottom, and the hardness depending on the temperature at which it's quenched. By the way, it's part of my job, so I hope I know what I'm talking about.
