Ordered this as well as the 2.5mm for a palpation and osculation simulator I've been contracted to build called the ACDET AbSim. We have many fasteners that go into stainless steel brackets or the stainless steel box that support the simulator. These bits being stainless themselves helps to prevent rust from forming in the future from using dissimilar metals. The drive system really does an excellent job of preventing wear from heavy use, and there's been no stripping the tool bit or fasteners so far. I've been using them for 2 and a half months working on about 15 different sims, and i couldn't be happier with the quality of these Wera hex drive bits.