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If you don’t have access to immediate medical help and need to get a ring off right away, you can cut most rings off with common household tools. However, this must be done with extreme care to avoid the risk of further injury to the hand and finger.  Never attempt to cut a ring off of your own finger. Have another person cut the ring off for you. Only try to cut a ring off at home if other methods have not worked and you cannot get professional help. A small steel circular saw blade can be used to remove rings made of gold, silver, or platinum. This may also work for titanium rings, but it may take several minutes to make the cut successfully. Diamond blades are more effective for harder materials, such as titanium or stainless steel.  Insert something metal, like the blade of a butter knife or the handle of a spoon, between the ring and the finger in order to prevent the skin from being burned or cut. Hold the blade to the ring for a second or two at a time, and lubricate the ring with a few drops of cold water between cuts to prevent overheating. Cut through the ring in two places, e.g. on opposite sides of the finger, to make it easier to remove. Do not attempt to use a blade to cut off a tungsten carbide, stone, or ceramic ring. Some hard-to-cut rings, such as titanium or stainless steel rings, can be snipped off with stainless steel bolt cutters. You will need to make two cuts on opposite sides of the ring to remove it effectively.  Use extreme caution when using bolt cutters to remove a ring, as you can easily cut the finger with either the bolt cutters or the crushed edge of the ring band. If you can, slip something between the ring and the finger, such as the blade of a butter knife or a thin piece of foam padding, to protect the skin from getting snipped or lacerated.  Bolt cutters will not work on a titanium ring with a wide band (i.e., more than 5-6 mm, or about ¼ inch, in width). Tungsten, ceramic, and stone rings cannot be cut. However, they tend to be brittle and relatively easy to crack. Take a vice grip and adjust it until it fits over the ring, and then clamp it down on the outside of the ring. Release the vice, tighten the screw a tiny amount, and clamp it onto the ring again. Repeat this process until the ring cracks.  Wear protective goggles if you have them, as small pieces of the ring may fly into your face when the ring cracks. Do not try to slide the cracked ring off, as this may cut the finger. Instead, pull the cracked pieces away.

Summary:
Cut off a ring at home as a last resort. Use a rotary tool with a mini saw attachment for soft metal rings. Cut off a tougher ring with bolt cutters. Crush a tungsten, ceramic, or stone ring with a vice grip.