Trying to cut some rings out of sheet stainless steel (1.5mm thick). Have mounted the sheet as shown (diameter is about 80mm)
- posted
17 years ago
Trying to cut some rings out of sheet stainless steel (1.5mm thick). Have mounted the sheet as shown (diameter is about 80mm)
Looks like you are using a tool without clearance / relief especially on the outer ( larger ) diameter of the groove you are cutting - the bottom edge of the tool is just rubbing on the partly cut groove making lots of heat & also work hardening the stainless - making cutting even harder - your wood backing is in danger of catching fire ! I usually use a tool made from a broken centre drill stub mounted in a piece of square bar with a cutting edge ground on. I have never seen a "tailor" made tool to do this, the nearest thing might be the small round boring bars that take a HSS bit ( think Chronos do them ) Good luck, Mark G.
I have a broken centre drill!!! I'll get onto it...
The cut off tool you are using is no good for the job. The double groove is because of the parting off cutting action that folds the swarf smaller than the groove it cuts so clearing the tool. It has no side clearance to speak off when trying to cut a circle.
The tool shape you need is like a knife tool in the lathe with clearance to the outer side of your disc and on the bottom.
Cutting stainless needs a sharp tool and stainless workhardens if the tool is not cutting cleanly.
Use the minimum amount of width on the tool you can get away with without the tool breaking.
You did not say what speed you are using. This matters. 30 ft/min or so is enough for cutting a tricky job in a tricky steel with an HSS tool, so something like 40 rpm would do with. That is next-to-bottom back-gear on a Super-7.
The tool needs a bit of top rake on it too.
PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.