[mattgray_92]

Hey guys!

Im new to this website and am searching for hopefully an answer to our ongoing problem. We have been machining alot of Dart Aluminum Blocks which contain the ductile iron sleeves. Idk if anyone has came across these themselves or not but they are harder than ****! We are running a Kaiser Boring Bar which holds a smaller triangular cutter, and the only cutter which has seemed to hold up (which isnt very good still) is the RT212 from Rottler. I do a .025-.030 total rough cut, then finish out with a .010 total cut. It has been using all three sides of the cutter to get one block done, which when boring just a standard cast iron block the cutter will last for weeks! Has anyone came across a cutter which can handle the ductile iron?

Thanks,
Matthew Gray

[HCE]

Have you presented this question to Dart?

[mattgray_92]

Yes i have, and they sent me over to Rottler which they provided us with the RT212 cutters. Someone out there has to carry a cutter which holds up. Kaiser sent me a sample cutter to try, and it didn't even make it through one bore without laying down.

[Jim Dawson]

The only thing I can suggest is CBN, ceramic, or PCD inserts. Not sure if any of these would work, but they are all hard. Maybe a Sunnan boring hone would be a good choice for a different process. They'll remove material amazingly fast, competitive with boring.

[mattgray_92]

Jim,

The cutter which Kaiser sent us for a sample was alcrona coated carbide, which he stated he cut stainless steel with good results. But when i cut the first bore the cutter absolutely laid down at the end.

[Jim Dawson]

An insert that works in SS is not necessarily good for ductile iron. The chemistry and physical properties of the material is completely different. I would talk with Kennametal and Ceremet application engineers and see what they have to say. There are inserts that are designed for ductile iron applications.