Maintaining a sharp skill saw blade is important not only to getting a nice even cut on your building material, but also for keeping you safe. Dull saw blades can have a kickback effect that can make the blade jump and cut you instead of the material you are working on. To prevent this from happening, always do a routine check of your skill saw blades and sharpen them regularly. Keeping your blade sharp will also make it last longer.
Secure the skill saw blade to the saw housing with a pair of vise grip pliers. Remove the saw blade from your circular saw by loosening the locking bolt with an open end wrench.
Secure the saw blade in a vise with rubber grips so the vise does not damage the blade. Secure the blade firmly, but be careful not to tighten it too much.
Mark one of the saw teeth on the top of the blade with a black marker to give you a starting point. Every other saw tooth will be beveled toward one side. Start by sharpening every other tooth that is facing the same direction. Using a diamond file begin with the marked saw tooth.
Hold your diamond file at between a 15 and 20-degree angle. Use six smooth strokes, up and back to sharpen your blade. When you have gone all the way around, turn the blade over and mark one of the teeth on that side as a starting point.
Repeat the process by sharpening every other saw tooth on the remaining side. When you have completed the second side, place the diamond blade at a 90 degree angle to the blade, across the face of one of the teeth. Run your file once, up and back across the face and repaeat this around the entire saw blade.
Apply a thin layer of 3-in-1 oil to both sides of your saw blade with a clean cloth to prevent rust. Wipe the excess oil off with a dry cloth.
Reattach the skill saw blade to the saw with the bolt and open end wrench. Verify that the locking bolt is tight.