If you figure it out please post back up. I've been having a helluva time getting any kind of good results with steel. Granted I have no idea what I'm doing and I've discovered that the material I was working with most recently was not what I thought it was (some unknown grade of stainless rather than the 4140 I was expecting) so that all has a huge role to play in this. Even so, it would be nice to run a 3/8 tool instead of the 1/4 for a bit of extra rigidity. I have some new tools from Lakeshore Carbide that I have not tried yet and a couple blocks of (for sure) 1018 so I'm hopeful I will have better results this time around but in general I like the properties of 4140 and would prefer to use that whenever possible for my steel needs.