I have modeled a real M12 * 1.75 bolt. I have created the threads by a sweep helical cut by using the necessary profile of the thread. There is no problem at all by sw2003 on modelling a real threaded bolt.
But when it comes to use the model for an analysis by an other software, I need to select upper surfaces of the seperate ring like features of the thread, but sw creates them in such a way that they can only be selected as a whole surface. If u look at a threaded bolt, U can easily see that in reality they are all independent surfaces ( the upper surfaces of the thread) Splitting curve on them for splitting is nonsense , in nature they are splitted, but when it comes to selection , they are a whole. For try, I splitted a vertical line on them, it splitted the whole structure wrongly, u can select parts of surface, but when u select 2 of those parts some of on the upper ring while some is on the lower. U can not select 2nd or 3rd ring as a whole correctly.
How can I overcome that problem???