Chainsaws have three basic components: the body, or engine component; the bar and a chain. It may also come with a protective chain cover. The primary thing to keep in mind when assembling your chain saw is safety. The cutting links are extremely sharp and can cause severe cuts even when the chainsaw is not running.
Lay a clean cloth or blanket on a hard work surface. Lay out the engine component, bar and chain on the cloth.
Turn the nut securing the chain sprocket cover to the engine component counter-clockwise until it is free. Remove the nut and then the chain sprocket cover.
Put on the heavy-duty work glove. Lay the chain into the grooves around the bar, beginning with the nose of the bar. Ensure the cutting blades on top of the bar are facing forward.
Pull the chain taut toward the back of the bar. Slide the bar onto the stud bolts. Slip the chain around the engine sprocket. Replace the chain sprocket cover. Replace the nut and turn clockwise to secure it in place.
Insert the screwdriver end of the bar tool into the adjustment screw. Turn the screw clockwise to tighten the chain until there is no slack on the bottom of the bar. Ensure all links are settled in the grooves of the bar. Tighten the nut.