There are a few key differences between brazing and welding that affect their overall strength. First, the temperatures used during brazing are generally lower than those used in welding. This means that the metals being joined together don't expand and contract as much during the process, resulting in a stronger joint. Second, brazing filler metals contain no iron, so they create a weaker bond with the base metals than welding filler metals do. However, this can be offset by using a stronger braze alloy or applying more pressure to the joint while it's cooling. Overall, brazing is not as strong as welding, but it can still produce strong joints depending on the materials used and how they're applied.