Getting fine powder boring hardened steel with carbide.

[agfrvf]

Boring a hardened steel sprocked with a shaped and honed brazed carbide on my atlas 918. I am making slow progress getting fine magnetic powder and occasional spark. No blue chips. I don't think it should be this hard. Thoughts?

 

[cathead]

Either the material is really hard or it's the cutter or possibly "feeds and speeds" related.

 

[chips&more]

File test the sprocket. If it’s too hard, you may have to grind it.

 

[agfrvf]

Hardened High carbon steel. It skims right off. I am making progress but this is brutal

 

[bluechips]

Need more info... spindle speed and dia. of bore.

 

[agfrvf]

Ran my boring bar in reverse and much nicer. Sounds like tearing paper instead of shreiking, nicer looking chips. Monster lead angle is the solution?
~500rpm going from 1/2" to 1" bore.

 

[woodchucker]

Ran my boring bar in reverse and much nicer

Really, I'm not understanding that. More info please.

 

[agfrvf]

Pulled out of the work instead of plunging into.

 

[markba633csi]

Sounds like you found the magic touch- it lets you know when it's cutting right

 

[agfrvf]

Here is a pic of the tool and the finished product.

Recipe;
~500rpm
0.050DOC
Whatever the lowest feed rate on the 918