The links of a standard chainsaw blade are specially designed with hooked cutting heads on the outer edge and shaped tabs on the inner edge that keep it aligned in the groove of the chainsaw's blade arm. Occasionally, when a chainsaw blade has been removed for sharpening, or a spare blade has been folded for storage, the blade can invert itself. You must right the chain in order to mount it safely on the chainsaw.
Lay the inverted chainsaw blade on a bench or flat surface. Unfold the blade so that it is in a single loop with all of the cutting heads pointed inward.
Elongate the blade so that it is equally rounded at each end and the straight sides are approximately 4 to 6 inches apart.
Grip the opposite sides of the chain wearing work gloves to protect your hands from the cutting heads.
Twist the sections of the chain within your grip to where the cutting heads of the chain are rotated outward as they normal are when mounted on the saw arm.
Hold the chain firmly in both hands to prevent the cutting heads from turning in your grip and pull your hands horizontally apart until the chain is taught between them. The cutting head side of the blade will snap over so the cutting teeth are on the outside, as required to install it on the chainsaw.