So far as we all know 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.
Of course what we discussed above is mainly for flatbed trucks and some other kind of vehicles, there are another kind of ratchet straps for semi trailers, ratchet e track straps , these tie down equipment will be used with E Tracks installed inside the semi trailer. By estimation, there are almost 80% trucks on the road are box trucks, so these e track straps are supposed to the most popular ones by volume. 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. It’s easy to understand that why e track straps are not as strong as regular ratchet tie down straps, inside the box truck the loads already have strong support, at least there is no risk of falling off, all the e track straps will do is to fixate the loads more than tie them down. With the help of e track cargo bar, rope tie off and some other e track tie downs and accessories, it’s pretty easy to secure loads inside the box trucks, but easy doesn’t mean not important, you still have to look out for any risks may present in the process of transportation, so secure your loads as reliable as you can, use the right tie down equipment for your job.
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, in the mean time the design factor of grade 70 tie down chains is 4:1, so the chains can support heavier load, and are more resistance to abuse, such as high/low temperature, moisture, while tie down straps usually only work well under normal condition. The most common materials in making tie down webbing are nylon and polyester, which serve different tie down applications. The typical application for nylon webbing is motorcycle tie down, while polyester webbing is ideal for tying down concrete pipes. When making the webbing, we have to take following characteristics in to consideration, the breaking strength, elongation, abrasion and the environment. When making tie down strap , manufacturer has to follow the recommendation of breaking strength and elongation requirements, when it comes to abrasion and environment, there are much more variations to be considered.