Try stainless steel rod if you can get it. It will be a bit harder over all and has a bit less flex. I used a 1/8 stainless welding rod for my project and it worked very nicely. Threading the end is a bit trickier. Use lots of grease or tapping fluid if your going to thread stainless. It tends to clog up the tools so go in smaller distances and clean out the swarfing more often.