system
Given the following post, respond as if you're commenting on Reddit:
human
In sword making, is it possible to fold the blade too many times ?
gpt
MSE here, definitely no. Folding doesn't weaken steel, but does enhance it's mechanical properties by increasing it's homogeneity.

Folding carbonized iron into steel, such as before forming it into a blade, was a technique used by smiths that did not have the technology to properly smelt iron. To be clear, it's not strictly a sword-making technique, either. 

One doesn't fold the steel into the shape of a blade, folding is just the process of refining the steel. It's by far the crudest and most difficult way to make steel, and what you get is not a molecularly uniform alloy, even after folding the steel thousands of times. Every "fold" starts and ends with a roughly rectangular hunk of iron riddled with carbon impurities. By hammering it out and folding it on itself, these impurities are very slowly blended together to form an alloy that approaches the characteristics of a perfectly homogenous steel alloy, the goal of the folding process. 

You can observe that even genuine Japanese Katanas, which are folded "thousands and thousands of times", are still visibly impure on a microscopic level. The reason behind the incredibly complex and even ritualistic techniques behind the katana's construction, maintenance, and use as a weapon stem from the fact that Japan had very little iron and created their raw steel in literally the most difficult, time-consuming way possible.

If, however, you decided to fold the steel millions or billions of times, you would theoretically have perfect homogeneity and therefore the best mechanical properties possible with that composition.