Practical approach to milling sheet metal

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[@ROBRENZ]

You taught me a new technique! The few stainless sheet jobs I have done were a nightmare like your dramatized beginning. Never to old to learn something new and thanks for your great content. ATB, Robin

[@StefanGotteswinter]

Thanks robin! Good to hear the learning never stops :-)

[@camillosteuss]

Oy, glad to see you around Robin... Been a while since you posted anything, i guess you are flooded with work, so i am not going to bitch... It`s not like i don`t rewatch your videos every so often, just as i do with Stefan`s work... Hope you are doing well! All the best and kind regards! Steuss

[@Ray-zu4mt]

I wish you would have shown this technique a week ago would have saved me a lot of heart ache. Never mind I’ll start again and put your info to good use. Many thanks.

[@tomboxyz5564]

The one thing I learned about drilling/milling/turning stainless is to use water. Basically flooding it with water keeps the temperature low and prevents stainless from hardening. At work we use cheap hole saws in stainless and they last a long time as long as you cool them with water

[@Steve_1401]

It's very rare that I cnc sheet, but sometimes I have to do 1.7mm cold-rolled. I picked up a couple of cutters the same as I use on my wood router at home - downcut spirals that tend to push the work down. (The sheet has a wood backer the same as you showed).

[@StefanGotteswinter]

I have yet to try downcut spiral cutters - Do they well?

[@Steve_1401]

@@StefanGotteswinter They're very good. I use the same method as you - fairly shallow cuts and faster travel - but still suffered with chatter and vibration with 'normal' mills, especially on the breakthrough pass. The sheet wants to catch, grab and pull up at any opportunity - there's just not a lot of rigidity to it. Downcuts help a lot.

[@daveharriman2756]

Actually this is very helpful to me, as I've just had a nightmare in the workshop trying to mill stainless sheet, so this video is timely, albeit a bit late for me, I could have done with seeing this before I ruined my cutters! but now I'm a bit wiser, so thanks for this.cheers, Dave

[@Chris-pb3se]

Really enjoy your vids Stefan. I’ve been a hobby machinist for 20 years (stress on ‘hobby’) and i always enjoy how you break down details so i can not only learn how but why. Thank you

[@georgedennison3338]

Well done in all aspects. I have a few projects using thin metals I've been putting off for lack of knowledge/expetience. I feel much more confident I can take them on, now. Close to 10 yrs ago, I was in the market for my 1st lathe or mill. Looking for a machine, I saw an ad for end mills, '40 pounds of end mills, $35.00'. Knowing nothing about end mills other than they aren't cheap, I went to look at them. 95% were brand new, some still in the rubberized protective coating. Got them home & was looking at one, to chk the cost on the 'net. My heart sunk when I saw the corner of the flute chipped off. Being ignorant of something, the 1st thought is, 'No wonder they were cheap. They're effed up.' Started looking at each end mill. At the 3rd-4th, I realized they were all 'chipped'. By then, I began to get familiar w/ them & realized the 'chips' were very uniform. It was then I understood they weren't ruined & it was a great deal, after all. I got a lathe that same day, but it wasn't until last year before I got a mill, (cancer detoured me for 4+ yrs) & I've been able to put the 40# to some use. I've read a lot & watched a lot of vids about end mills & milling in the intervening years. You are the 1st to discuss anything about chamfered flute ends, their use or even their existance. Thanks. GeoD

[@angelramos-2005]

Very well explained,Stefan.Thank you.

[@JohnBare747]

Stefan thanks for another very helpful in depth tip/trick. Always enjoy your tips and musings, First Rate Stuff!

[@nicholashacking381]

Massively helpful! Sehr hilfreich. I wish I'd known this, two years ago, when I tried to make myself an instrument panel by milling sheet steel clamped to plywood. It was a total dog's breakfast. (Früstück des Hundes?) I concluded that a Bridgeport was not a sensible machine to use on thin sheets... but you have shown me that it can be done, if one knows how. Thank you.

[@MartsGarage]

Thanks Stefan. That was very interesting. I was an expecting an April Fools joke but I'm glad I watched. All the best, Mart in England.

[@philbert006]

I've always had good results using adhesive and sticking it to your backing board.

[@StefanGotteswinter]

Yeah it works well - But I am always annoyed by the sticky residue that gets pulled up by the cutter and smeared across the side walls of the material cut.

[@cogentdynamics]

Wow, thank you! Have resorted to my contouring saw and drill. Can overcome the 304 with high speed drills sometimes but sometimes I saw the drill come out of the sheet metal with a reduced drill diameter. Yikes. Tricky for me like an amateur.

[@Aussiemachinist07]

great video Stefan, Another one to go in my apprentice training playlist.

[@DunderOz]

Thank you. Another wonderful and important tutorial 👍🏽

[@1Hundling]

At the end the view reminds me on this old tonys bench, black shirt and way of filming his stuff

[@cennsa140driver]

Thanks for the sheet metal tip, I didn't know that!

[@AmateurRedneckWorkshop]

Thanks for that information. Thanks for the video keep on keeping on.

[@ProfRonconi]

Just what I needed to know! Thanks, Stefan.

[@iteerrex8166]

Thanks for the lesson, Stefan 👍

[@Mike40M]

As always, interesting. Two questions. At first, I thought that helix angle was reason why full depth cut, giving more axial force, was reason for vertical vibrations. Then you compared two endmills which had different helix angle. Confirmed my thought. Then came the mill tip discussion explaining advantage of best tip geometry. Is helix angle important? Second thought. 50 years ago, I learned about then quite new research by Sandvik about boring bar chatter. They found that increased feed sometimes gives no chatter. Is this still correct and general knowledge now?

[@CraigLYoung]

Thanks for sharing and Happy Easter to you and your family 😅

[@dominic6634]

recommend getting a laser cutter lol! use to mill a lot of sheet metal.

[@StefanGotteswinter]

Trumpf doesnt want to send me a full size laser cutter for free :-|

[@dominic6634]

@@StefanGotteswinter 😄 that's inconsiderate!

[@johnnycab8986]

Is the chamfer also pushing the sheetmetal down into the backing plate to negate chatter as well?

[@StefanGotteswinter]

It has a tiny vertical force component, but I dont think its doing much influence on the overall process.

[@daynosdr]

Why not use a downcut endmill?

[@simonhopkins3867]

Ah Dr Evil we meat again. 🎵Dum Dum dahhh🎵

[@kkupsky6321]

I once was with a model named Beverly Shear.

[@StefanGotteswinter]

I once meet somebody who was 3mm stainless sheet.

[@kkupsky6321]

@@StefanGotteswinter that’s tough.

[@StefanGotteswinter]

@@kkupsky6321(But yeah, I have a nice bench shear that cuts up to 4mm mild steel sheet - But the cut is no where near the quality of a milled cut)

[@yamsoussana]

hey Stefan, you used 0.1mm DOC on the CNC, what is the highest limit ? 0.2 ? 0.3 ? thanks.

[@StefanGotteswinter]

On the cnc I even went only 0,05mm per pass. I would stay below/equal the chamfer width of the endmill. Multiple passes on a cnc cost nothing but time, but give a more robust process.

[@mpetersen6]

A 4mm endmill at 2000 rpm is just over 25 meters per minute. Call it 80 feet per minute.

[@wrstew1272]

Your cheap ply is better than ours 😢

[@kmpnelson]

Are those clamps behind you 3d printed...

[@StefanGotteswinter]

What clamps, at which point in the video?

[@gamerpaddy]

they look like 3d sls printed stainless steel

[@fxm5715]

@@StefanGotteswinter I think he means the hold down straps and step blocks.

[@kmpnelson]

@@StefanGotteswinter I just noticed them at the beginning, the grey makes it seem like they're printed however I believe I've seen you use that style of clamp many times.

[@StefanGotteswinter]

AH! Those are regular steel clamps / step blocks made by AMF, for some reason they paint them grey.

[@prodigalson2670]

Where is the other more effeminte guy that looked similar to this one?

[@StefanGotteswinter]

That guy hasnt shaved in 2 days.

[@ryderjay326]

Id have cut that on bandsaw in 1 minute

[@StefanGotteswinter]

If the cut is clean enough for the given purpose, thats fine.

[@thelastofthemartians]

@16:30 I'm guessing you didn't mean to cut out a profile of Donald Trump ..."like we've never seen before" 😅

[@Jbomb-ep4jr]

Stefan you’re a brilliant teacher. I finished my apprenticeship a decade ago and still learn something new every time you post a video. Thank you!

[@TeslaAtoms]

At 12:45, my hand was throwing away my cup of coffee and reaching for the E-Stop.... I broke more than one endmill milling flat sheets like this, held down by clamps not modeled in CAD. Personally, i love those kant-twist clamps. Problem is, my endmills hate running into them at G0🤣Also, at 15:50, i would highly recommend using two clamps. Otherwise, the cut off piece tends to rotate below the clamp, getting pulled into the cutter.

[@Cancun771]

I guess this is the closest thing to an April Fool's joke that we're gonna get on this channel.

[@wrstew1272]

He did a great one in the past…..

[@derKarl_stp]

oh Stefan has had some good ones up his sleave in the past... trust me... he knows what he is doing

[@bradyoung6663]

This is a lucky coincidence. I have to do this exact thing Monday morning. Same material and all.

[@rexmundi8154]

Using the painters tape / super glue hold down works great but be careful with really thin stock because you’ll destroy the material prying it apart. I soak it in acetone

[@RotarySMP]

Excellent video Stefan, as always. Thanks for sharing your knowledge and expertise with us.

[@StefanGotteswinter]

Thank you!

[@rlsimpso]

Great advise on using chamfered corner endmills. I recall you mentioning those before and I really need to order some. In addition to clamping the waste stock, using tabs helps keep off cuts from getting thrown around and jamming. I do a lot of milling of ~1mm (.040) aluminum sheet on a small router. Using the tool probing and material mapping helps with the initial cut on GRBL based CNC routers. It helps to use a sharp pointer to do the mapping with a slow Z feed to avoid deflection on thin sheets. The control then compensates for the height variations and it really cuts down on burrs. I have not seen this feature in real CNC machines, but i assume anyone running those has a better processor for cutting sheet metal.

[@andrewdolinskiatcarpathian]

Thank you Stefan for the masterclass. Interesting and informative from beginning to end. 👏👏👍😀

[@neilh2150]

Excellent video, answers a lot of problems I've had with sheet metal milling looking like someone chewed it off ! You know I'm going to learn somethng when Stefan gets the pen and paper out ! Thankyou !

[@Blondihacks]

Great technique! I’m curious about your thoughts on left-hand helix endmills for sheet metal? Robin has demonstrated this- they apparently push down on the work, eliminating vibration and also reducing burrs. I haven’t tried it, but it seems promising.

[@StefanGotteswinter]

Thanks! Nope, I have no experience with them, but I heard that they are very helpful in low rigidity situations. But I wonder how they compare in a low-depth-of-cut approach, since the spiral flute is almost not engaged at all.

[@bruceanderson9461]

Absolute wonderful video! I have never given this process any thought and would have done this machining operation in one pass. Thankyou for sending me on the right path1

[@DavidM2002]

Depending on the size of my raw material and the size of the finished part, I will use a spray mount adhesive to mount the metal to the wood. The adhesive is gives an extremely strong bond so you can clamp the material much farther away from the cut path which means it's less likely to bow. Also, I will sometimes use Medium Density Fiberboard (MDF, AKA Medite) as it is usually far flatter than your average piece of plywood. If you use coolant it will pretty much destroy the MDF but that's a small loss. To remove your part from the MDF, apply a bit of heat from a heat gun and the glue will soften and release the part.

[@peterbonham5540]

Another masterclass from Stefan, but the "neglectable" at the end puts a smile on my face

[@ColchesterBridgeport]

Yes, I'm going to use that from now on. Sounds better.

[@peterbonham5540]

@@ColchesterBridgeport Yes I used to work with a Russian guy who regularly made inventive use of words that when you look at them closely, were not incorrect. I think here "negligible" would describe the burr, "neglectable" describes his attitude to it.

[@steinmargunnarsson3709]

Thank you Stefan, for this lesson. As you explained it, it became obvious that your approach is how it should be done.

[@godfreypoon5148]

My endmills usually develop an edge chamfer after I try to use them.

[@gwharton68]

Always learn something new watching your videos. Thanks.

[@TheRecreationalMachinist]

Thanks for sharing your knowledge and experience. I'm a little wiser today 👍 🇬🇧

[@dwegmull]

So the fastest way to mill sheet metal is to speed up the video 10x 😉

[@stefanhertweck]

Thx for sharing this tip, very useful. I also (sometimes) hava to fiddle around with sheet metal, and in stainless you have to watch out for workhardening. Gruß aus dem Badischen, from another Stefan :)

[@stevensmart8868]

Another great video Stefan. The chamfer on the end mill at high feed is forcing the material down into the spoil board. I wonder if the edge finish improves with a aluminium spoil board so there is less micro material movement. Maybe the spindle bearings are loaded up just a little more with the chamfer cutter also. All these small things that make a difference are long in the learning, but with the help of your excellent videos, im sure most of your viewers are getting bettrr results more often. Thanks again.

[@Suzaru87]

Ich nutze meistens meine Vakuumspannplatte für Blech. Dadurch ist es von der Höhe her sehr gleichmäßig. Ab und zu nutze ich auch die Technik wie du sie hier zeigst. Das Abfallstück sichere ich mithilfe von 2-3 schnellen Bohrungen mit dem Akkuschrauber und ein paar kleinen Spaxschrauben. Dadurch hat man auch keine Störkontur durch eine Klemme.

[@tacitus101010]

Very informative and helpful video. Thanks for posting, I know it's a lot of work to make these videos so please know it is appreciated!

[@OneWheelDrive365]

Thanks Stefan you're brilliant. This will help me a lot. I'm planning to make kant twist clamps. And that's a lot of cutting in sheet metal.

[@mpetersen6]

I made a set years ago out of stainless. They were a pain to bandsaw out due to work hardening. I used them a lot but they were actually too big for the plate l used for the sides.

[@chrismayer8990]

Danke für den Tipp und die ausführliche Erklärung! 👍

[@P1-Engineering]

We do quite some stainless sheetmetal (13-8PH) and to be honest never had issues with just going full slot and as fast as possible. Key is the fixturing imho. I only use precision milled aluminium plates as a backer and drill a bunch of holes to really clamp down the sheet. Think this also helps with getting the heat out of the sheet and into the aluminium. All roughing is done with a 6 mm 3-flute from Garant and finishing with a 4mm 6-flute. And a VMC with TSC to get the chips out of the slot also helps..😅

[@bcbloc02]

Sharp edges cut great but are a fragile thing. Radiused or chamfered endmills are much more durable in my experience.

[@khalifayousef4782]

as always Mr. Stefan you educate us with another informative video ! thank you for all you do and taking the time to show us.

[@pauldorman]

Thanks Stefan! Great tips. Given the minimum chamfer available from your supplier seems to be 1 mm, do you think it would be worthwhile using a tool & cutter grinder to add a custom chamfer on occasion? I'm thinking if someone had quite a few cutouts to make, a smaller chamfer, perhaps also at a higher angle, might allow you to reduce the number of finish passes required, and perhaps a higher angle could increase the downwards force on the work and reduce the tendency for it to be pulled up by the cutter. Edit: perhaps I should have said "lower angle"? I mean one with less Z and more Y.

[@alanbrown4446]

Very useful. I just milled some stainless sheet and the end mill (about 6 mm dia) was fine for the first 20mm. Then it got red hot and end of cutting. I was cutting full sheet metail thickness. Then I swapped to another cutter and used very small DOC as Stefan describes. OK job. Great to see Stefan is describing exactly what worked for me. Thank you Stfan - pity I didn't see you video before I started my job!

[@StefanGotteswinter]

Bummer you burned up the cutter, but great that it worked out well in the end :-)

[@colemine7008]

I use double stick tape and leave two tabs to keep things from flying on the cnc.

[@stumccabe]

Excellent and really useful tips. Thanks!

[@rexmundi8154]

Great video and very informative. I’ve been using the super glue and painters tape hold down method like NY CNC on an aluminum plate for thin stuff and it works great. Actually, not just thin stuff. It works great at anything I want to get around without worrying about the clamps. If I don’t hold it in the vise, I’m probably gluing it to a plate. I even glue pieces of aluminum scrap to the top of the vise hard jaws to make soft jaws out of for smallish parts. You’d be surprised how much force it takes to break them loose. For really thin material, you need to use heat or solvent to break the bond because prying them apart will actually bend the part

[@StefanGotteswinter]

I used that method too several times, but usualy ditch the tape and superglue the material directly to an aluminium plate - Its a bit more annoying to get rid off again, but the higher rigidity is worth it for me (Also thickness tolerances can be hold tighter if necessary)

[@ade63dug]

Great info Stefan . saved in the grey matter for reference . Cheers Ade.

[@EPaulIII]

Stefan, this is a great video. I have liked milling cutters with a chamfer for a long time. I even "save" the ones that get their corners worn by hand-stoning a chamfer on them. But I have never thought that a chamfered end mill would be good for thin/sheet metal. Along with taking shallow cuts and using a high feed rate, I have really learned something today. Thanks for a great video!

[@624Dudley]

Thanks Stefan, I think I have learned a lot here. 👍

[@StefanGotteswinter]

Good to hear, thanks for watching :-)

[@kimballanderson5758]

Stefan, I've been dealing with this very issue today trying to get a good clean cut on a customer's part. God bless you! I changed my approach as you suggested, and i am now going to be able to deliver descent parts. Cutting .8mm 316L Stainless Sheet using 1/16 inch diameter end mill. Now my cut matches the mirror finish on the material! Beautiful!

[@greggraham247]

I will be trying this approach on cuts that need it. This, id scribe, band saw, one rough and one finish pass at full depth.

[@StefanGotteswinter]

Sawing and finishing is always a great alternative, if the contour allows it.

[@greggraham247]

@@StefanGotteswinter Not trying to be a dick, but then show that contour. Maybe it's just me, but I find it unappealing when the test piece makes no logical sense to the demonstrated tool path.

[@StefanGotteswinter]

@@greggraham247Well, have some phantasy. Unfortunately the parts that i in the recent time did where all no-show/NDA. anything thats a small later-to-be-stamped part. anything that requires larger numbers, where babdsawing is not efficient. Anything that needs more than outside contours. Open up a moder GFI switch or a modern breaker switch - any of the sheet parts in there.

[@mhdm]

Another aspect: For slotting (on home shop/less rigid machines) the 3 flute endmills work better than 4 flute ones. Which kinda makes sense with lower cutting and pulling forces (from flute helix). The surprising bit is that 3 flutes also work better than 2 flutes. With 3 flutes the load (both magnitude and direction) on the cutter varies less whereas with 2 flutes when one flute starts disengaging the other starts engaging. This results in the cutter forces making an almost 180 deg switch, producing bad vibrations. Worse, because the shock loads happen when the flutes are engaging the sides of the slot, overall the slot will end up oversized. Actually, the same shock loading will happen when slotting with endmills with any even-number of flutes though the shock will be less for 4+ flutes and expensive variable flute geometry cutters. But don't just take my word, make similar slots with 2, 3 then 4 flute endmills at the same chip load (or less scientifically same feed) and listen for vibrations and measure the slot width. Do check the runout (on the flutes) of each cutter beforehand as that can easily be bad enough (from bad collet, spindle, debris or wear) to invalidate the test.

[@kylewarren69]

My approach to sheet metal is to have someone else laser or waterjet it.

[@StefanGotteswinter]

Yep. Or dont even mess with it at all.

[@camillosteuss]

Huh, knew of this from a while ago... I think i was watching some Sandvik promotional/educational video on high feed insert cutters or such, when i first saw/heard of this... Tho, tooting my own horn ain`t really what i want to say here... What i want to say is that with a decent cutter grinder you can make such chamfered corners on the cutters without issue... I mean, Stefan, your deckel s1 can turn any endmill into a 45deg edge cutter... Same thing as one would sharpen a carbide reamer... The main 45 angle and the secondary or secondary+tertiary relief compound angle right thereafter for clearance and voila, a high feed shallow cut cutter... Hell, is there a better thing to do with an endmill whose edge or few of them have chipped off(i will do so with my 7mm Walter cutter that i fucking managed to drop and nick one edge like a bloody imbecile that i am)? Instead of grinding it down and having to keep the whole face definition/geometry while doing so, you an just chamfer the edges, be they broken or not and you have saved yourself a lot of effort, while getting a neat cutter which leaves a very strong corner in deep slots or can do stuff like what you have shown here... Of course, that is predicated on the broken edges not being smashed off in an overly brutal manner where half the flute is missing, but that goes without saying really... All the best and kindest regards! Steuss

[@bobengelhardt856]

Would it work to take the first passes at 0.1mm (0.004") until the surface is broken all round and then take much deeper cuts? Even full depth?

[@godfreypoon5148]

I copied this design for my flux capacitor and it ended up sending me forward in time several hours! 😟

[@valkman761]

Are there online resellers in Germany for these Hoffman group stuff that would ship inside EU? When trying to register, I'm forced to handle my order through an another company in the group and they maintain some ridiculous requirements on their customers.

[@garymallard4699]

I use that technique in wood or plastic or metal cutting.... it takes a little longer but usually it is almost as fast..taking deep cuts heats up your blades / tool and is harder on your Power tool too... shallow multiple cuts are going to be easier on your tools ..reducing the heat and force needed to make the cut depth.. . it is something i learned about 40 years ago and i find it the best way to do cuts.... i don't care if it " seems " to take longer because i know it is going to allow me to do the cuts without problems every time....especially when using Piwer tools that are just powerful enough but doing long cuts it is going to overwork your tool and the cutting tools too... you can relax and get alot done if you are patient.... 🇨🇦🤓🤟

[@dsfs17987]

tool life in that dramatic recreation, in my experience of dodgy SS part milling, wasn't actually that bad, your endmill made it to the end of the cut 😅😅

[@strykerentllc]

Another excellent tutorial Stefan. Hope all is good in the land of precision machining and Black Forest cuckoo clocks. Cheers!

[@RustyInventions-wz6ir]

Very interesting. Thanks. I’m sure it going to be very useful.

[@williammills5111]

Many thanks once again. Very concise presentation, valuable information.

[@fijs653]

high speed comes from cutter materials improving from steel to hss to all kinds of alloys and coatings nowaday.

[@swanvalleymachineshop]

That is one to remember for sure . Even for large cuts on my other mill ( 4 1/4 ton Stanko ) with a face mill i often go the multiple lighter cuts, high reed & rpm . Seems quicker & less load on the machine . 👍

[@gerritvisser]

I recall from one of your previous videos/lessons that you used a continuous down spiral with low step down from Fusion 360 for pockets in thin materials. Similar to what you are using here. I kept that recipefor futurre use. Thank you

[@StefanGotteswinter]

Yes! Exactly, for internal cutouts or continous contours I will spiral the entire contour with a small pitch like 0,05mm/pass.

[@midwestcyberpunk]

Stefan- I just got a Mill and I'm trying to get a lot of helpful accessories for it. What do you call the part that sits in the T-slot table and squares the sheet metal/wood up with the table?

[@midwestcyberpunk]

as seen right behind the endmill @ 3:59

[@raindeergames6104]

Stefan I know this is a bit of and "old" question. Years ago Yiu did a video about tramming the column of Your mill and Yiu use something callef Diamand machine epoxy or something like that. Do Yiu have the correct name for that product and mayne a hint as to where to find some?

[@StefanGotteswinter]

The product is called "DHW", made by the company "Diamant"

[@johnharding2912]

Would you say this could be used on titanium sheet? Be keen to know what speeds/feeds youd recommend on fairly beefy router/cnc. Great video!

[@johnharding2912]

My software says 0.0139mm/tooth for Ti, 667mm/min @ 12k RPM with a 4 flute so, I will give it a try. 16cm3/min MMR doesn't seem too bad.

[@googacct]

Does having the chamfer on the endmill also help with pushing the material down? I have tried cutting sheetmetal on my cnc in the past and the results have generally been very poor if not outright disasterous to my cutter.

[@StefanGotteswinter]

There is a tiny vertical force component by the chamfer, but its not the main effect at work here.

[@CraigHollabaugh]

Very helpful. Air starting/wood thickness variance and end mill discussion are my takeways. Thanks from Colorado.

[@tristanpatterson3843]

Those little stainless needles give me nightmares.

[@BruceBoschek]

As always, excellent description and discussion, understandable and convincing. Thanks for continuing to share your experience and expertise!

[@vr66luke]

Fantastic info as always.

[@bobodyuknow]

What is that endmill holder?

[@StefanGotteswinter]

Which one? On the manual or the cnc machine?

[@bobodyuknow]

​@@StefanGotteswinter on the manual deckel

[@erikisberg3886]

Thank You Stefan for this very useful advice! I have used MDF board similarly, find it much flatter than plywood. Usually glue a piece of hardwood to the back for quickly putting it in the vice for less critical stuff. Easy to attach clamps around the sides.

[@Smallathe]

Awesome demonstration and explanation, as always. Thank you!

[@brettclarke8892]

Thanks. I will give it a try

[@Rustinox]

Indeed, that works way better. It's all in the details. This is something I think I would never have figured out myself.

[@PracticalRenaissance]

Very good info, thank you!

[@billshiff2060]

From my experience, Your method is good and the chip thinning fast feed is sound . Most machinists only deal occasionally with stainless so getting a good understanding of it is difficult. I had the good or bad luck to work where we did ONLY stainless for 10 years. Thats when you find out eventually that most of the charts and book recommendations are bogus. The actual successful sfm is ~1/3 the recommended sfm. From my experience for your 4mm carbide setup it would be ~ 2100rpm vs the book recommendation of ~ 6500. You don't really want to see blue chips, no darker than honey with coolant. For HSS endmill it would be ~730rpm vs book recommendation of ~ 2000. For HSS you don't want to see any color on the chips. Keeping sfm down will keep your tools alive in stainless. Then you can creep up on it to find your max. Strange story. I had a #7 drill bit that for years , drilled thousands of holes in 304 and never got dull. and a DO-ALL 1/4-20 tap that tapped thousands of holes without getting dull or breaking. I have never been able to find either in any catalog !😡 I STILL have them 20 years later.

[@Cancun771]

But isn't laser-cutting the way to go these days?

[@StefanGotteswinter]

If leadtime, tolerances and side wall finish permit lasercutting, yes.