At least a race of a blank for forming a bearing raceway member is hardened by heating and is finished to predetermined precisions. In one implementation, a computer-implemented method provides keyword searching. The closure includes a polymer-filled channel which connects the top panel to the skirt. The first power switch has a first switch terminal connected electrically to the second node, and a second switch terminal connected electrically to a third node. The control circuit receives the rotation speed signal to judge whether or not a paper jam occurs according to the rotation speed signal. In certain embodiments of the present invention, this is accomplished by a method comprising formulating an abrasive slurry solution of predetermined acidity, treating a chemical mechanical polishing pad with the abrasive slurry, disposing magnetic heads on the chemical mechanical polishing pad and lapping and grinding the magnetic heads for a predetermined period of time.