OK, here starting a box truck business will talk about something familiar to many truckers, ratchet straps, as you can see, there are two words, ratchet and straps, and you also guessed right, the ratchet straps are assembly of ratchets and webbing, think about cam buckle straps? yeah, they are cam buckles with straps! Relatively weak, the cam straps are most seen inside box trucks and on passenger cars. Ratchets are another story, the hardware is pretty strong, and because of it's mechanism, the ratchet could be pretty small and fairly large, you will be able to find 1''-4'' ratchets around, and the breaking strength is often as weak as a few hundred LBS to as strong as 16,2000 LBS, it's pretty versatile compare to all or any other truck tie downs.
It's estimated that 80% trucks are box trucks, and the e track tie down system is just for semi trailers, so e track straps are hottest cargo straps. And these straps are not as strong as the one we use on flatbed truck, the working load limit of typical e track straps is 1,000lbs, with minimum breaking strength of 3,000lbs. The working load limit of 2' e track straps are lower than other 2'' truck straps, simply because the truck wall provides support for the strain and prevent the strain from moving if stacked properly, but you still need to make sure the strain in your truck are secured properly and the way to secure them work.
According to cargo securement standard, the look factor of ratchet assembly is 3:1, meaning that the breaking strength of the tie down is three times of the working load limit, this means that a relatively forgiving work place, on the other hand the design factor of transport chains is 4:1, which indicates the chains will undoubtedly be better suited for tough conditions, such as very high/low temperature, moisture, as the aforementioned truck straps are only for normal conditions.
The truck straps usually created from polyester, which includes low elongation and less elastic, which is perfect for tie down truck load, since we don't want the strain on the truck bed to go or budge. When making tie down straps, manufacturer must follow certain guidelines and pass DOT inspection, this implies all the straps made for tie down purpose have to meet all of the requirements imposed by FMCSA(Federal Motor Carrier Safety Agency) and follow the guideline of WSTDA and ASTM.