几何尺寸与公差论坛------致力于产品几何量公差标准GD&T (GDT:ASME)|New GPS(ISO)研究/CAD设计/CAM加工/CMM测量

几何尺寸与公差论坛------致力于产品几何量公差标准GD&T (GDT:ASME)|New GPS(ISO)研究/CAD设计/CAM加工/CMM测量 (http://www.dimcax.com/hust/index.php)
-   American standards (http://www.dimcax.com/hust/forumdisplay.php?f=81)
-   -   ansi 9standards0 code issues - using a thead for a datum (http://www.dimcax.com/hust/showthread.php?t=20195)

huangyhg 2009-09-05 05:59 PM

ansi 9standards0 code issues - using a thead for a datum
 
ansi using a thead for a datum
can you ref a thread as a datum?
yes. but indicate minor dia for internal thd... or major dia for external thd.
and then you will still have a fun time trying to inspect it.
if possbile, create a small cbore or shoulder to a tight tolerance and use that as the datum instead. you will have to position the thread to the datum, but the extra step makes inspection much easier.
--scott


所有的时间均为北京时间。 现在的时间是 12:45 PM.