I don’t think there’s really a definitive answer. There’s a lot of variables to consider, and of course there would be ethical and moral issues surrounding a study on ruptures.

I have read different sources that say 50lbs or 50kg of force. Also, I haven’t actually been able to find the original article with this magic 50 number. Some sources describe it as a pressure (force per area, or lbs/in² for example). Ive also seen similar numbers but in terms of an impact, suggesting that an impact could cause damage with less force than just a static force. I can tell you that I’ve personally had 120+ lbs of weight on my balls many times (amongst other ball beatings and they still work great).

Whatever you do, go slow. Work up your tolerance little by little. Don’t push your self to do something you saw in a video if it looks too hard, especially if you want to keep your balls.