Turning cast iron, carbide or HSS preferred?

[MarkM]

You know stupoty I am going to start wearing a mask from now on. Thanks!

 

[Titanium Knurler]

Stu, was just kidding, of course. It is a serious topic but just struck me as humorous for some reason. Mike

 

[Cooter Brown]

Grey cast will make HSS scream super load but Ductile iron cuts very nicely with HSS..... Grey cast makes powdered chips and Ductile iron makes curly chips that look like 12L14 chips....

 

[darkzero]

I sometimes ware a dust mask when turning cast iron, when I don't my nose blows are a very cast iron graphite colour

Stu

I was making 2 chuck back plates the last time I machined CI & didn't wear a mask. When I went to wash my hands & face my nostrils were black. My dinner also tasted very irony that night for some reason.

 

[Cooter Brown]

Here are some pictures from when I cut a back plate for a lathe chuck that was made out of grey cast.... I had to use carbide to cut this type of cast iron, I tried HSS and it made the loadest screeching sound I have ever heard so loud that I started to lose control of my hands lol....
It made a massive pile of powder...

I chucked my 6" 3 Jaw in an 8" 4 Jaw to turn down the back plate OD to match the chuck.....

This is a South bend Heavy 10 with a 3' bed....