It’s a fact that when assemble tie down strap and ratchets together we get ratchet strap, by this logic the cam buckle strap is just the cam buckle with tie down strap, why I am not surprised? Cam buckle tie downs are only for light duty use, and 2” cam buckles are the biggest size we will see in the real world use, and it’s still light duty. Compare to cam buckle the ratchets are stronger and more widely used, the available sizes of ratchets are 1”,2”,3” and 4”, and the ratchet buckle generally has higher working load limit than the cam buckle, with 3,333LBS, 5,400LBS working load and a design factor of 3:1, these ratchets have 10,000LBS and 16,2000LBS breaking strength respectively, which are pretty strong for most tie down applications.
So far we discussed about tie down devices for flatbed trucks or similar transportation vehicles, we will see there are other kind of trucks, the typical one is box truck, and most of them have E Track installed inside the truck, for these rigs we use e track straps. In fact box truck has much bigger share than flatbed truck, the percentage maybe around 80%, of course this is only estimation but you get the idea, and the conclusion is that e tack straps are by far the most popular tie downs. The e track straps usually have working load limit of 1000lbs, which is only 30% of the 2” flatbed tie downs, and the breaking strength is only 3,000lbs based on design factor 3:1. It’s understandable that e track straps have lower working load limit, because the box truck wall will provide strong support for the loads inside, and the truck wall will prevent the loads from falling off, rolling over, tilting and some other dangerous movements. You also have e track cargo bar, decking beam, rope tie off, etc. at your disposal, with e track tie down straps you will be able to secure any kind of cargo , make the hauling experience more pleasant than ever , but remember that you can never be more careful when it comes to your precious cargo and truck , make sure your cargo are tied down properly all the time.
We already discussed the design factor of ratchet straps, it is 3:1 and for the record all this says is that safe load limit of tie down straps is 1/3 of it’s breaking strength, for comparison purpose we know that the binder chain has a design factor of 4:1, which basically says that for the chains the working load limit will be 1/4 of their breaking strength, which indicates that tie down chains are designed for tougher environment than tie down straps are in. Nylon and polyester webbing are used in making tie down webbing, for different applications people will choose different material accordingly. Nylon webbing has better elongation than polyester, so for shock absorption wise nylon is ideal material while polyester usually is used to make tie downs for heavy equipment. Elongation, tensile strength, abrasion and environment, these have to be taken into consideration when making tie down strap. Breaking strength has to reach the recommendation level no matter what, and elongation has to meet the requirement, abrasion and environment sometimes are not that clear cut, when designing tie down we may have to consider the most extreme conditions these tie down straps may be in, or we may just consider the normal transportation environment.