i want to buy nylon or polyestern string, but i cant pick which one. i need theone thats the hardest to break

Hardest to break? I’ve heard really good reviews on the durability of Twisted Stringz Project X. Pure poly, soft, and very durable.

is yoyoexpert polyestern string harder to break than kitty nylon string?

Go buy some low-number steel fishing line and make your own strings! I dare you to break those!

Oh, and be current on your tetanus shot first!

I’m not really sure you can answer this question reliably. The string durability has almost everything to do with your play and the finish on the yoyo, which can either eat a string every few hours or every 2 weeks. The best thing to do, imo, is just buy a 100 pack and change the strings regularly so you never have to worry about it. It’s not like they’re expensive.

Plus, string material is a performance issue. Poly, cotton, and 50/50 strings play differently. You are probably better off choosing the one that matches your skill level and play style than just making do with the one that’s most durable to save a few dollars a year.

Anyway, if we’re talking about strength of string alone, the kevlar string should be able to take any of the more traditional synthetic and natural fibers. It does come at the cost of a heavier and more rigid string though, so it doesn’t work as well for slack tricks in my experience.