Surface Finish

[mikey]

C's and 6's are only going to apply to inserts, correct ?
I do not see how it is possible to grind a true chip breaker in a small (3/8) size HSS tool.

You actually can grind a chip breaker into a HSS tool but it just isn't worth the time and hassle to do it, at least not in my opinion. Even with inserts, light cuts produce strings in mild steels. If you want chips from these materials, take big bites and increase your feed rate. Under these conditions, even aluminum will chip.

 

[Hoghollor]

Hey All,

Should i be able to achieve a smooth to the touch finish with a 1942 South Bend 9? I'm using HSS tools. I started out turning a rusty piece of 2-inch A-36. All the rust is gone, and getting close to my final desired diameter 1.500. But no matter what I change (spindle speed, feed speed, depth of cut, tool end, oil), I cannot achieve that smooth finish. I still feel slight discrepancies when I run my finger across it. I've attached a photo, but I do not believe you can see much in it. My best finish comes from a high spindle speed (690), shallow cut (.002), round tool tip (~1/8"), with oil.

Is it my technique, the lathe, the material, or the phase of the moon? Let me know if there are any questions i can answer that may help in formulating an answer.

Thanks!

What material are you cutting? Are you using home made cutting tools? If you’re cutting steel you probably need to slow rotation down I’m thinking to around 185 or so