As Pedro linked in a previous post, some of the straps don't reach the rated figure. This is all for a slowly applied "static" load in a controlled environment tho. Dynamic loads are different and therefore a material's behaviour is different. In the real world a fast snatch recovery (not recommended, but common method) could be considered a dynamic load due to the large rate of load increase.
Winches wind in a drum which slowly increases the load on the cable until the 4wd moves or something breaks. It is a much slower rate of load increase to a snatch recovery, and is much more controllable
Cheers
Dan

