I needed to cut a 3/4 inch hole through a double walled stainless steel container. My hardened steel drill bits just scratched it. My Titanium coated bits, didn't do much better. I ended up getting a pair of cobalt steel step drill bits. I read that the best method of drilling stainless is with a slowly turning bit, and a lot of pressure.
My arms were getting tired, but eventually a small hole was formed. Once the tip broke through, the step part of the drill made relatively short order of making the hole larger. Since I wanted the hole to line up perfectly I continued to drill through the first hole to the outer shell. With a lot of pressure, the outer shell started to dimple. It struck me that perhaps a grinding tool could cut off that dimple and make a small hole. That worked! The second hole was drilled much faster than the first.
I had to make one more hole in a separate piece of stainless. I decided to put a dent in it with a nail punch, I ground that dent off, and then I was able to punch through it, and ground that flat. The step drill bit made fast work of the rest.
IMO, a cut off saw a must have tool. For me, it belongs in the same category as a sawzall. A tool I rarely need, but there are times when no other tool will do.
My arms were getting tired, but eventually a small hole was formed. Once the tip broke through, the step part of the drill made relatively short order of making the hole larger. Since I wanted the hole to line up perfectly I continued to drill through the first hole to the outer shell. With a lot of pressure, the outer shell started to dimple. It struck me that perhaps a grinding tool could cut off that dimple and make a small hole. That worked! The second hole was drilled much faster than the first.
I had to make one more hole in a separate piece of stainless. I decided to put a dent in it with a nail punch, I ground that dent off, and then I was able to punch through it, and ground that flat. The step drill bit made fast work of the rest.
IMO, a cut off saw a must have tool. For me, it belongs in the same category as a sawzall. A tool I rarely need, but there are times when no other tool will do.