划线中心角度尺(图1)由中心尺1,V型规2、盖板3、螺钉9,5组成,在中心尺的T型尺上刻有刻度,可根据三角函数的原理,将圆周划成任意角度,也可等分圆周。划线时,首先将V型规靠紧圆型工件的侧壁,中心尺靠紧圆型工件的平面,用划针在工件上划出圆的直径,然后,用 Marking center angle scale (Figure 1) by the central ruler 1, V-shaped gage 2, cover 3, screw 9,5 composition, the central ruler T-scale engraved with a scale, according to the principle of trigonometry, the circumference Into any point of view, you can also divide the circumference. Marking, first of all, the V-shaped relying on the side wall of the circular workpiece, the center ruler circular workpiece close to the plane, with the needle drawn on the workpiece diameter circle, and then with