Steel with 5 Flute Endmill

I’m thinking about milling steel. I’m probably thinking ahead as I haven’t even gotten around to doing aluminium yet but I got this 5 fluted endmill. I think it’s like a 3/16 endmill. I wonder if the five flutes will make it easier to cut steel on the mpcnc. Chip clearance isn’t as big of a deal because it’s steel, not aluminium. The five flutes gives it a greater cutting capacity each revolution. I thing that might be a decent thing to have on the mpcnc. I’m also thinking that at 30,000 rpm in my DW660 that’s just more flutes to create a ton of friction with instead of cutting. I don’t know. Anybody here have any guesses? I think the endmill is carbide, not sure, it is definitely coated in something.

The more flutes, the slower the end mill should run. Or the faster the machine should move. We’re not rigid enough to move that fast, so you need less flutes at the 660’s speeds.

Technically steel should be cut with a cnc mill, not a cnc router, different tools.

A larger number of smaller chips is unfavorable when it comes to heat. 20,000 to 30,000 rpm is already making many small chips but there is also the torque and stiffness to consider, so chips can’t be too big anyway, i.e. a slow, high-torque spindle will have other problems.

Five flutes is moving in the wrong direction. Wood might tolerate 5 flutes with some burn marks, but steel is likely to have runaway heat and then the tool dulls in a few seconds and then it spirals from there.

3/16 at 30k is almost 1500ft/min. You’re gonna cook that thing.
Jamie is right. Rigidity is going to force you to take smaller step overs, which will make you feed faster to make chips. More flutes means “even more faster”. And the faster you push the steppers, the easier they lose steps.
You definitely want to slow down the spindle, and then you lose torque. Check into the pid controller and see if that’s something you can handle. If not, maybe the super pid or a spindle. I moved to a 611 because it will hold speed.
How large is your build?