区别：倾斜度公差——位置度公差（Angularity Does Not Locate - Use Position Tol

yogy

区别：倾斜度公差——位置度公差（Angularity Does Not Locate - Use Position Tolerance）
http://www.dimcax.com/gdt_web/march-07.htm

倾斜度不能定位——优先选用位置度
Angularity Does Not Locate - Use Position Tolerance
如下图所示，为了保证槽中心平面与基准B一致，10mm的方槽应优先选用给出位置度公差要求。若只给出倾斜度公差要求，倾斜度只能控制60度的角度，而对槽中心平面与基准B一致没有限制。若为了更好地控制槽的角度，可在给出位置度公差的基础上，还可给出倾斜度公差要求。须牢记一点的是，对特征而言，定位是首先考虑的因素，定向是其次考虑的因素。

Here is another case where angularity cannot fully define the feature. The original drawing had angularity rather than position applied to the 10mm wide slot. The drawing shows that the center of the slot should be in line with datum axis B. Angularity would assure that the slot is at the 60° basic angle but ignore that the slot center plane should pass through the datum axis. To keep the slot in line with the datum axis, position needs to be applied to the slots size dimension. If the angle of the slot needs to be controlled better than the angularity provided by the position tolerance, an angularity tolerance may be added as a refinement. As we teach in our GD&T seminars, for features of size, locate first with position and refine with orientation, in this case angularity, only if necessary.

[url="http://www.dimcax.com/gdt_web/march-07_files/march-07a.gif"][/url]
  

yogy

英文讲解动画视频参见
http://www.dimcax.com/gdt_web/march-07_files/march_07.wmv
英文讲解内容见上原帖内容。

simonzeng

谢谢!

simonzeng

Thanks!!