Using a poorly honed tool vs a well honed one is the same as cutting with a dull vs a sharp knife; both will cut but the sharp one does it much better. Honing is a skill. Like all skills, it comes with understanding and practice. Try to remember that your goal is to remove grinding marks and make the face flat across the entire face. If you can do this for all three faces, their intersections will be dead sharp and will not reflect light. I'm no pro but I have honed hundreds of lathe tools and if I could pick one thing that makes a difference it would be your mindset: you are trying to make the flat ... flat.
Wow! I used a scrap piece of 3/4" 12L14 rod and was able to easily take off 0.030" and 0.040" when using a 0.004"/rev feed rate. At 0.050", it was bogging down and chattering until I changed the feed rate to 0.002"/rev.
I'm a believer!
On a 1-1/2" piece of 1144 "stressproof", I was only able to go to 0.020" per pass, but this might be because of the larger diameter. Or, it could be the tougher material.
Now that you accept that your tool can improve the performance of your lathe, you need to learn to use it. Start with the tool perpendicular to the work and find a depth of cut that causes your lathe to chatter, like that 0.050" deep cut you made in 12L14. Now rotate the tool to the left about 5-10 degrees and lock it down, then take that same cut and see what that does; I will bet the tool cuts without chatter. Mess with this tool angle thing (aka changing the lead angle of the tool) to see what your lathe wants to deliver max performance for you.
Now that your tool can rough better, see if it can take a micro-cut. IF the tool is honed well, it should be able to take any micro-cut you can dial in. Try taking a half-thou cut and see if the OD really reduces by 0.001". Then take smaller and smaller cuts and see if the OD reduces as expected. My lathe tools will take a 0.0001" deep cut accurately.
You will find that how big a cut a lathe can take matters little in a hobby shop. What matters is how small a cut it can take to bring you in on size. With a carbide insert, dialing in a micro-cut is difficult due to the impact of the nose radius. With HSS tools, things are much simpler and more direct.
Once you determine how big and small your tool will cut, learn to use your edges to enhance finishes. I discussed this in the body of this thread; you might want to go look for it.
Learning to use your lathe tools is important, whether you use carbide or HSS. Learn the strengths and weakness of both types and pull out the tool that the job requires. On a small lathe, most of the time, HSS will be a better choice but for some jobs you will need to use carbide. Learn how to choose an insert and how the nose radius dictates your cuts. Know how tool angle matters, even with carbide, so you can get the results you need. The only way to learn this is at the lathe; you cannot look it up on the net because the published info is for industrial lathes that most of you do not own. Once you know what your tools can do on your lathe, you are free to make a choice.
