Stainless steel ties have a clasp at one end. The rest of the tie will be flexible and rollable. Most of these ties have a self-locking mechanism inside the clasp that only works in one direction. So, in order to lock the cable all, you have to do is to roll the tie and slide it into the clasp at the other end. Depending on the size of the cable and the bundle, you can tighten it as much as you want. However, keep in mind that if you tighten the tie too much, it can affect the exterior insulation of the cable. So, the tightness should be just enough to keep the cable from moving around.