Stihl Rollomatic E Super Light chainsaws bars are 30% lighter than their solid steel counterparts. Bars are made machined from a single piece of rigid steel, then hollowed out on one side and filled back with a lightweight material. The reduced weight improves the chain saw balance. The replaceable sprocket nose tip is securely fastened by three rivets. The nose sprocket is sealed to keep dirt and corrosive material out, therefor never needs to be greased. Rails on the bar and nose are induction hardened for long life. Angled oil delivery hole increases flow rate and reduces clogging of lubricants.