A scale assembly of a table saw includes front and rear outer slide members disposed at front and rear ends of a slide mechanism respectively; front and rear inner slide members disposed at front and rear ends of a table assembly respectively wherein the front inner slide member slides in the front outer slide member, and the rear inner slide member slides in the rear outer slide member; a block member secured to a front end of a rip fence assembly and including a channel and a spring biased member; and a lever in the channel and including an exposed trigger, a projection, and first and second recesses. In a locked position, the spring biased member has one end entered the first recess and the projection enters a lengthwise cavity on an outer surface of the front outer slide member.