Just received my order of index-able boring bars today. Five boring bars, 6-12mm with inserts for $29.99 and free shipping. Gave one a quick try in brass. Cuts like butter and hope it does the same with steel. This is the 6mm bar. Probably the max on the Sherline. Others will work on my MaxiMat7. I have several types of boring bars and my least favorite are brazed bars.