[DavidhCNC]

I am using a Torchmate cnc plasma cutter to cut 1/2in low carbon steel, the parts then go into my Haas for milling. It seems that these plasma cut parts may be eating up my carbide cutters rather quickly. I was running about 260 sfm at 14 ipm when my last 1/2in end mill disintegrated after only a few parts. Could it be that when the part drops into the water after being plasma cut that it aborbs carbon and is somewhat case hardened? Any one have any experience with this?

[plain ol Bill]

Plasma leaves a hardened carburized edge after cutting steel. If you can remove a few thousandths with a grinder before milling it should go much easier.

[JPMach]

Don't climb mill on the cut edge, let the teeth get under the edge and bust it out rather than pound through it. It still sucks but its better

[jimcolt]

There are different types of plasma cutters....and this is not mentioned in the original post.

-Air plasma cutting will create a Nitride hardened edge on steel of bvetween .006" and .010" thickness. A few passes with a grinder can remove it before machining. This is like a case hardening of the edge and it is caused by the 80% nitrogen content in the plasma jet.

-On industrial plasma cutters such as Hypertherms high definition class HPRXD plasma...Oxygen is used as the plasma cutting gas on steel. This leaves only a slightly hardened edge on steel...and can be directly machined, can be welded without porosity, and can be formed without cracking.

So, as long as the correct plasma is used for cutting steel....you can machine the plasma cut edge easily.

Jim Colt Hypertherm

I am using a Torchmate cnc plasma cutter to cut 1/2in low carbon steel, the parts then go into my Haas for milling. It seems that these plasma cut parts may be eating up my carbide cutters rather quickly. I was running about 260 sfm at 14 ipm when my last 1/2in end mill disintegrated after only a few parts. Could it be that when the part drops into the water after being plasma cut that it aborbs carbon and is somewhat case hardened? Any one have any experience with this?

[DavidhCNC]

Ok thanks guys.

It is an air plasma cutter. The parts are kind of an odd shape, so grinding them may not be an option. I guess we are gonna go through more end mills...