Hi all, thank's for responding. We are not sure about 'welding': We also found this tool in our vertex-modeller. But this tool is just melting/welding two vertexes into one. Also all selected vertexes are weld to just one vertex. This is not what we has in mind. We needs something like.... select n-vertexes, let the tool compare all vertexes. If there are any two vertexes with nearly the same coordinates, make them equal. Or ... like our headline says ... choose two vertexes, select one master and equal the slave with one click. Right now we have to copy each coordinate, paste it to slave and add a '0' behind, because our RDS-program is just showing two rounded decimals (is there a setting to show more decimals? Didn't found it). Much work work, if you have tp prepare more than 500 vertexes.... We developed a little program with Delphi, which compares all vertexes and make the job, but this program is not usable in case of big *.obj with many lines. We are short in time to build up a SQL-Databases to make the comparison a little bit faster. So this was our idea to ask, if there is any tool for this subject in Carrara/RDS which we didin't found yet. Thanks to all Daniel