hello all my name is paul i live in fairford gloucestershire england i have recently taken up tree climbing and i am adicted i cant wait to get out and climb i am lucky as i work on the land so i get to sneek off and practice i climb to 40 feet or so not got the courage to go higher yet but i will with a bit more practice anyway my question i weigh 17 stone or 108kg or 238lb i still look at my gear and wonder if i am too heavy my carabiners are rated in kn how:unsure many of me would they safely hold regards paul

Fear not! A carabiner rated at 25 kn will hold 2549.290532445 kg or 5620.2235775 lbs. of force in a fall. You're not going to break one climbing!

thankyou that is reasuring maybe now when i get to 40 feet and look at my carabina and have doubts your words will ring in my ears and maybe i will climb higher regards paul

My pleasure. Remember though: Always use triple action, positive lock carabiners that are in good condition when climbing trees. If the gate gets opened by twigs or leaves, the strength is greatly reduced.

Be safe, have fun, and climb high!

Baker wrote:
Fear not! A carabiner rated at 25 kn will hold 2549.290532445 kg or 5620.2235775 lbs. of force in a fall. You're not going to break one climbing!

And is it correct that the "working load" is considered 1/5 of the max rated load, or 1124 lbs?

It is my understanding that WLL varies from manufacturer to manufacturer. Some will say that WLL is 20% of breaking strength, some 25% - static force. If you're asking if a 25kn carabiner will hold 1124 pounds static weight, gently applied - I believe it will.

Carabiner ratings are _base_d on lbs. force not static breaking strength. I will not pretend to be a mathematician or physicist. I do understand, though, that the force applied to a carabiner when a certain weight is caught by it during a fall is FAR greater than if the same weight is gently and easily hung on the biner.

Simple solution...don't fall. Keep everything snug and you'll be fine. Don't lose sleep over the strength of a biner as long as it is in good shape and from a reputable manufacturer.