Using your Bosch T118AF100 jig saw blades is easy. First, make sure your jigsaw is turned off and unplugged. Then, insert the T - shank blade into the blade holder of your jigsaw until it fits securely. When you're ready to cut, start with a slow speed, especially if you're new to using jigsaws. For smooth and efficient cuts, apply light pressure and let the blade do the work. Remember to use a proper lubricant when cutting metal, as this will reduce friction and extend the blade's life. As for maintenance, after each use, wipe the blades clean with a dry cloth to remove any metal shavings or debris. Store the blades in a dry place to prevent rusting. If you notice the blade isn't cutting as well as it used to, it might be time to replace it. These blades are designed for cutting sheet metal and thin metals, so don't use them for other materials like wood or plastic, as this can damage the blades.