Comments by "Paul Frederick" (@1pcfred) on "Best Annular Cutter? Fein, Milwaukee, DeWalt, Euroboor, Hougan, Hermes, S\u0026F, Evolution, Steel Dragon" video.

@NOTNOTJON running carbide dry is common standard practice. You do it because you can run carbide about 4 times faster than HSS. At that RPM fluid flies everywhere. So it's a bit messy. To each their own though.
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@EnlightenedSavage tungsten carbide can run much hotter than HSS can. Chips carry heat away from cuts. When you're cutting with carbide tooling you should be throwing blue chips. They got blue because they got that hot. That temperature is no sweat for carbide either. But you do you.
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@timso522 cast iron is not steel in any way, shape or form. Although I can see how the stock may confuse people that don't work with it. But as soon as you cut into cast iron the difference is clear then. Cast iron will not throw chips. Whenever I work with cast iron I get the distinct impression that the stuff is just consolidated dirt. The swarf cast makes looks like dirt. It makes me dirty too. So if you were to use any fluid with cast iron you'd only make mud. You can use compressed air with cast iron. That makes a mess too but it can work. Cast iron also has a different thermal transfer rate than steels do. Considerably different. Cast iron is much more heat conductive.
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@nachoisme it depends on the tool and the material. Cast iron is cut dry. Cutting fluids can improve the finish with aluminum and steel.
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Tungsten carbide doesn't really need to be cooled. That's because tungsten carbide has a very high melting point. 2,785–2,830 °C (5,045–5,126 °F Carbon steel melts at 1425-1540°C (2597-2800°F) So what you're cutting would be a puddle long before tungsten carbide started to soften up. But you will get a nicer surface finish using some cutting oil. We're going in dry!
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What makes carbide suffer is lack of rigidity.
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@NOTNOTJON there are solid tungsten carbide tools. The most affected part of a tool will be the cutting edge itself which even with an insert is solid tungsten carbide. It is the delicate edge that is what is destroyed. Then once the edge goes things go from bad to worse. But if the edge withstands then the rest of the tool generally will too. Carbide is run dry in ferrous metal. Because it can. Lube iron and you're just going to make a mess.
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@jort93z High Speed Steel is a bit of a misnomer. It is higher speed than carbon steel but not much higher. The max cutting surface speed for HSS into mild steel is 100 SFPM Which here with a 15/16" diameter tool would be 407 RPM.
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A 15/16" tool spinning 250 RPM is 61.4 Surface Feet Per Minute. You could go up to 100 SFPM with HSS drilling mild steel. So that'd be 407 RPM You definitely need to run coolant/cutting oil. Here's the formulas for calculating that: SFPM = (π x Dia x RPM) / 12 and RPM = SFPM / (π x (Dia / 12))
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@ihatelogincrap hey when you're there with your buddy out in his driveway drilling out wheel studs it can get pretty abusive then. That triple gear reduction drill is really you!
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