Not true. I make my living making titanium rings, and have made probably around 30,000 titanium rings over the years. The first thing I did was cut a ring off of my own fingers using various methods including a ring cutter, hack saw, bolt cutter, and Dremel tool. You can cut through one fairly easily with a hacksaw. Although titanium can be hardened, it is not done so on rings. It has a Mohs hardness of around 6 or so. Stainless steel is similar in properties. I have had 4 customers that I know of have them cut off. Emergency rooms are equipped to handle it. Tungsten carbide cannot be cut by conventional means, but it can be cracked off in a vise or vise grips.