[求助]管螺纹的画法？？？请帮忙

legna

<img src="attachments/dvbbs/2003631654512916.gif" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2003631654512916.gif\');}" onmousewheel="return imgzoom(this);" alt="" /><img src="attachments/dvbbs/20036316542343282.gif" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/20036316542343282.gif\');}" onmousewheel="return imgzoom(this);" alt="" />
这是个G1/2''的管螺纹，经查表：大径D=20.955mm,小径d=18.631mm，请问在CAXA实体设计里应该怎么画这个管螺纹？？请给出详细步骤，谢谢！

legna

<img src="attachments/dvbbs/2003631795126094.gif" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2003631795126094.gif\');}" onmousewheel="return imgzoom(this);" alt="" />

请问应该用什么图素画管螺纹的外螺纹，如果把单位改成英制的话（如图），英制单位是什么？而且G1/2''的管螺纹有好多，应该选用哪一个？？他们的编号都是什么意思？比如：1/2-12 NUS
亟盼高手指点！！请不吝赐教！！

legna

难道就没有人帮帮忙吗？？

legna

各位版主、CAXA高手，请不吝赐教！！

lqy821821

请不要着急，以前都没有遇到过，需要试一试！