Dry Milling VS Milling with Coolant on Steel What do you do? 

The company I started at was the same everything was flood cooled. There is not much good info out there about this surprisingly. Thanks for watching and commenting!

@@mvpmachine so the flood coolant is not also not recommended? should not it prevent the thermal cycling/shock happening to the tool?

Thank you for watching and commenting! I always use coolant for aluminum and stainless, do you use coated end mills when you dry mill aluminum and if so what coating?

@mvpmachine Titanium DiBoride and titanium carbonitride is the name of the coatings. Depending on the part, sometimes I use coolant and sometimes I don't. Like many aspects of machining there are lots of variables. If you want to rough out aluminum without coolant then the main requirement is lots of power and a big chip. Usually only with larger endmills. I will run insert tools dry as well and those have fully polished inserts with no coating. But again, a large chip is needed. .014-.020 IPT on a 2" diameter shell mill. I have a lot of machines crammed in a 1500 square foot shop on my home property so my main reasoning is air quality. A 3/4" endmill at 18k RPM or a 4" shell mill at 10k RPM makes a lot of smoke and mist with flood coolant. Having 5 spindles running like that makes it almost impossible for anyone to work in there even with mist colllectors running non stop, so I had to find alternate methods that happened to be more efficient and more reliable.

@@pcsmachineworks You are packed in there with 5 machines going. We have the same issue when our CNC lathe is going full, tilt steam and mist and you go home with heavy lungs for lack of a better phrase.

Thanks Stuart! I am a coolant and cutting oil hater to a certain extent except for drilling and machining aluminum. It has made my life easier...But I do always use it on the CNC lathe.

I never looked, I will check that out, thanks!

yeah I guess it's called gun cuz it shoots a laser to let you know where it's pointing, and it's shaped like a gun, and it has a trigger (I'm referring to the ome I have, i can turn laser on or off)

Thank you for watching and commenting!!!

Thanks for watching!

Thanks Craig!

Thanks for watching and commenting! It is likeley the coolant could be causing some issues with the tool breakage as well as not enough of a cut. That material is relatively easy to machine but can work harden with an overly hot tool making the part hot then cooling it instantly. Air blast is relatively easy to rig to try it and not too hard to make a cheap sytem for permant use. It likely would help you. It is only used to get the chips out of the way to avoid recutting it is not meant to cool the part or tool the heat comes off with the chip. I hope your new job goes well!

@@mvpmachine Thanks so much! I will investigate further. It occurred to me that only a microsecond of inadequate chip evacuation loading up the tool/ recutting that could cause instant breakage. Also I have seen some cases here on YT of Toolox 44 being dry machined with maximum flute engagement. The technique makes all the sense in the world to me and when it does not work I think it's worth finding the cause.

@@bigbattenberg using as much of the flute as possible is easier on the end mill for sure. That material does not do well with small cuts it is similar to grinding it does heat things up.

This was not about aluminum as mentioned in the begining. And I disagree with your assertion that you need coolant to hold tight tolerances in steel, its just not correct. If you use the right tools and cutting methods you can do a job faster and with better results without coolant.

@@mvpmachine "If the conditions are right and the part you're machining has the correct shape, you can avoid the heat problem". This is what you're saying. Plus there's a problem of surface finishes of course. Everything's a tradeoff, every situation is different. Going dry 100% of the time has its tradeoffs. Sometimes it's simply efficient to trade the longevity of the tool for the result you're after. I've worked in turbomachinery facilities that are over 100 year old and must have invested millions of man hours in basically machining the same things and they run coolant on steel because of certain advantages. 100 years is enough to spot the results and the costs. Every approach has its limits, not every situation is the same.

@@chronokoks The old school shops used high speed steel and coolant is required, then came carbide without coatings and they still required coolant. It was not until the early 1990s that modern pvd coatings became available that enable dry machining to be possible. Most machinists and companies over use coolants and cutting oils because they learned in a different era and do not know better. The 2 end mills shown in my video have coatings that are pretty much ruined by coolant and they are the most commonly sold carbide end mills available today. Using coolant defeats thier intended purpose. That was the point of this video was to enlighten people that they might not be using these tools correctly and I have seen many people do that with these two types of coated end mills. I have seen people buy and use these 2 for aluminum oblivious to the fact that the coatings on these are terrible for cutting aluminum.

It's hard to go back to high speed steel after you try carbide! Thanks for watching!

Hi Dieter, Thank you for watching and commenting! What is the cutter you are using and coating?

Cutter ist from Gühring Alcrona Coating 35/38 and 4slots. Inner Coolant pressure 10bar. Works awesome.

Hi Steve, thank you for watching and commenting! I wish you and your son luck in your business ! I have a cat40 spindle in this machine and the tool holder in this video is a Nikken collet milling chuck I love them but they are pricey. I try to find them on eBay when possible. Most of my other tool holders are from a company called CME. They are local but sell nationwide www.cme-tools.com is their web site. They have the best collet style milling holders I have seen and are very affordable. I hope this helps, Tim

David they are TNMG 432 inserts any TNMG 431 and 432 works on the Suburban Tool Fly cutter

Hi Joell, unfortunately aluminum really needs coolant to keep it from sticking to the tools. And most coatings don't really seem to help much with cutting or tool life. I prefer uncoated carbide on aluminum because most coatings even the ones designed for aluminum rob a little bit of the sharpness from the tool in my opinion. PCD and CBN inserted cutters are possible options that I have no experience with so I cannot say If they are a good option. Thank you for watching and commenting!

@@mvpmachine - Thank you for the detailed reply as it definitively confirms what I imagined happens. I think I understand this all so much better now. So in other words, if the tool gets too hot the aluminum will melt and stick to the cutting edge. Carbide can handle higher temps than HSS. Although aluminum specific carbide tools are almost as sharp as HSS could be, they don’t break down and lose their edge when pushed hard. And when pushed harder (taking a deeper cut than HSS is capable of), the heat generated isn’t carried away by the chip because the thermal conductivity is so high. The chip is then so hot right at the cutting edge it sticks to the tool. Then making the tool edge duller, generating more heat and welding more chips to the cutting ‘edge’. It’s probably a lot more complicated than that 😉 Continuing on in the ‘cutting of aluminum’ theme, do you have any MQL vs Flood experiences you can share? (Maybe a future video?) I can see lots of benefits of flood cooling and I suspect it is superior in every professional setting. But in less optimized environment (hobby CNC) can MQL also be effective to keep the tool cool and have a high enough air blast to clear the chips from the slot? 🙏🙏

Hi, Thank you for watching and commenting! I think turning is a different animal on a manual lathe dry milling would most likely be fine for 99 percent of the operations. For parting I agree with a oil, coolant or lubricant because the tool tip is usually so small and that makes it tough to shed heat. Also chip evacuation when parting needs as much help as possible. For a CNC lathe I do believe in full flood coolant all the time due to the massive amounts of material that can be removed in a short period of time the workpiece can get too hot without it. I would be interested to hear other opinions on this but I always use full flood on the CNC lathe and it can steam up the shop pretty good.

@@mvpmachine thank you!

Hi, thanks for watching and commenting! The answer to you question really depends on what type of cutter you are using. With high speed steel your method is not bad, but with inserted carbide cutters nothing is needed and you may be hurting your tooling with oil. If you use carbide end mills I do not know that I would spend extra for the high performance coatings because it would defeat the purpouse, you likely can get them hot enough to work by using a slow feeds and speeds but that's not necessarily good for the carbide without the proper chip removal rate..Plain uncoated carbide will work fine dry but a small amount of oil would likely be beneficial.

@@mvpmachine excellent. That about matches my current use thanks!

Andy, my thoughts are for a CNC lathe it does not apply. The coolant likely does have a bad effect on insert life, but you can generate so much heat especially during rapid stock removal that it would likely be bad for the part. Our CNC lathe can steam up the shop preety good when we are doing production. On a manual lathe I would say in most cases except tapping and drilling no coolant works fine. Thanks for watching and commenting!

You did not watch the whole thing, I show my air blow system at the end. Thank you for watching!

Not true works on steel not aluminum, I know this well. Thank you for watching!

Reflective materials in general will do it, and yeah have seen my reflection in steel

@@StepSherpa i have burned my hand on aluminum before I knew this. If you check out my propane tank wood stove video, I show this same IR thermometer reading off of the stainless top up to like 500f.

​@@mvpmachine The wood stove video at about 11 minutes pretty much proves my point. You are measuring higher temperatures on the back and sides than on the top. That is probably because the sides are painted and the chimney is more oxidized. The top that is a cleaner steel surface probably reeds to low temperature.

@@larslindgren3846 The stainless is 1/4" thick compared to the less than 1/8" thick steel on the sides and stainless is a poor conductor of heat. the back shows more heat also because that is the exit where all the heat goes, also higher than the thicker stainless steel. If you look at the thumbnail on my other woodstove video shown here the red tells the story, ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Lhe9zpZAupM.html this was a pine fire and the whole thing gets crazy hot but the red is concentrated toward the back.