If you look at the weld, there is a mark on it. The marked part is the strongest part of the weld. There are marks so you can find them easily when you need to use a scissor jack. Some cars have a mark on the weld called the strongest. The mark is easy to find because it is different from the rest of the weld. But some cars do not have this mark, and many people use their jacks on either side of where the pinch is. This might work for some cars, but not for all of them or when they are using it as a jack stand.