If you’re pushing the tool too hard, the blades can snap under pressure.
The key to making your Multi-Functional Tool blades last longer is to let the weight of the tool do the cutting, and to apply light pressure only.
Not using the correct blade will also result in more blade breakages.
This can be done by looking at the blade tooth profile - fine teeth usually indicate a blade that can be used on metal, whereas a more aggressive tooth profile is usually only for wood.