1. Blade matching:
The key to making your sabers to be able to take a beating is to match like blade to like blade. You wouldn't duel with a thin walled 3/4 O.D. blade against a 1 inch thick walled blade. Even actual swords were not designed to be smashed against one another wildly with no concern for technique and a swordsman worth his salt would never in their right mind hit their precious blade against a tree or telephone pole to test its durability. That's just plain stupid.
2. Nothing is unbreakable:
If you use a tool for a purpose it was not intended for it may be able to do the job, it doesn't mean that it will do it well. I mean even riot shields that are made of polycarbonate can shatter under extreme stress. The purpose is to protect the person holding it, not be unbreakable. So when a sabersmith tells you that their blades are far superior to others because they hit a competitor's blade against a rock and the tube dents, it doesn't always mean it's an inferior product.
Like many people uneducated about actual functional swords, everyone is obsessed with rigidity but the truth of the matter is the harder a blade is, the more likely it is to shatter. That's why even thick walled blades can and do when under constant strain. Real swords, and lightsaber blades for that matter also need some flexibilty to be able to absorb a hit. That's why swords are tempered during the forging process to allow them to immediately spring back into shape if bent during combat. Granted, lightsaber blades for our purposes are round and if a real sword were to make contact with another sword blade it would be flat meeting edge, but the same principle applies to lightsabers. So a thick walled blade isn't always the best blade for dueling.
There is something to be said for thinner walled blades, and there is certainly something to be said for not smashing your investment violently against another saber and expecting there to be no consequence.
Hope this helps.