Review on Bosch 🔩 CO2139 3-in-1 Cobalt Drill by Johnny Black

Bought two of these in different sizes for drilling stainless steel. After extensively searching the internet for stainless steel drill bits, I found a post that seemed logical to me. The author noted that when drilling stainless steel, there is no point in lubricating the drill bit with oil or grease. The goal is to cut stainless steel without overheating it and the drill bit. Lubricants only cause slippage. So I put washers on the stainless steel surface I was drilling and left them filled with water. The water cooled the stainless steel and kept it from solidifying before cutting. Also, be sure to drill slowly as heat builds up faster at higher speeds. I've drilled dozens of holes this way and the drill bits held up. The Bosch bits outperformed the Century bits that I also bought.