I am taking a class for beginning solid works. When I created the mating parts, for the first part I used Hole wizard to create the thread (1-14 thread). on the thread shaft I made I created a 1.0 dia shaft and cut the thread on a 13.75 long portion of the shaft. When I try to mate the 2 pcs, I get a message for the shaft saying, (selected entity not valid for this type of mate). I chose mechanical/screw/rev's/in = 14. I was going to attach the files but I have no zip program only winrar. Does anyone have a suggestion as to why this message appears? Any help will be appreciated.