Mark,
You stated concerning contact:
For multi-body contact with mis-matched surfaces, Split Surface can be enabled (shown below) to split the surfaces in the region of interest. I think this discussion is about Creo's fastener tool, which does not create a solid fastener. I've used the surface region creation technique for solid bolts, with solid heads and nuts. But you could still split the surfaces with the interface tool. PTC developed the Split Surface function in the interface tool to save time in creating matching surface regions.
