Craftsman circular saws are portable, hand-held power tools, powered by either a battery pack or power cord. The saws have a round replaceable blade with several sharp teeth that rotates quickly to cut materials such as wood and plastic. As the saw is used, the material cut by the saw will slowly break-down the blade, causing it to dull. As the blade dulls, it becomes more difficult to cut materials and the blade will become nosier and draw more power. Many types of blades can be sharpened when dull, however, unless you sharpen the blade yourself, the cost of sharpening the blade will often outweigh the cost of purchasing a new one.
Turn off the saw and unplug the power cable from the wall, or remove the battery pack.
Place the saw on the side of your work bench so that the guard is lifted and the blade rests beside the table.
Press the "Spindle Lock" button, located on the top of the saw to hold the blade in place.
Insert the blade wrench into the center bolt on the blade, then turn clockwise to loosen. Remove the bolt and outer washer, then slide the blade off of the spindle and down through the blade slot at the bottom of the saw.
Place the new blade on the spindle, then secure the outer washer and bolt using the blade wrench.