[Newbie] Hss Vs Solid Carbide End Mills, Lessons Learned, Questions.

Carbide tools perform best when run dry or flooded with coolant. Intermittent coolant application can cause rapid cooling/heating that can fracture the tool. Water based coolants disperse heat the best. Cutting oils are thick and often sulfur based. They make smoke and don't dissipate heat as well as coolant. Cutting oil works well with HS tooling, since the SFM is much lower than carbide.
 
How deep is your cut? If you're milling a deep slot, chips tend to get stuck, so light cuts help. Another good technique is to plunge cut along the slot, then mill out the 'web'. Plunge cutting takes advantage of the most rigid axis of the mill.

For a mini mill, you might simply try a smaller end mill. Using compressed air can also help a lot. It'll clear the chips and provide some cooling. (There's also the added advantage of blowing chips all over the @$#*& shop!)
 
Not milling overly deep. Have been hitting it with heavier force, actually making chips, much happier with results. Turns out I was the issue (user error, typical, haha)

Will try compressed air!
 
Note, I rarely use cutting oil, I never use it with face mills, oil is what? Sticky, and the chips can't evacuate, they stick to the work, and the tool, then they get smashed into the work. I've heard that if you can't flood, then don't use oil, unless your tapping of course. I get superb finishes with no oil. And I'd rather have that than a little bit more tool life, which if your rubbing stuck chips into the work your causing premature wear to the tool anyway... something to think about, I only oil when roughing, and most times I don't oil

There's a much easier math solution to find rpm
SFMx3.82/cutter diameter
1018 is 350sfm with carbide, and you have a half inch tool
350x3.82/.500=2674rpm
 
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