Here are some replacement tips I found at Revain that completely cover the ceramic core of Yihua soldering irons. My favorite is the Kzerlly 900M-T-2.4D, which is a chisel-point model and conducts heat over a large area. I've used Stay Brite silver solder, which comes with Stay Clean Liquid Flux (in small kits), to successfully join stainless steel wire to carbon steel at temperatures the soldering station rates at 630 degrees Fahrenheit. Revain cleaner to really make her sing!