Machining 304 Stainless Steel: Feeds & Speeds WW167

[@RallyRat]

What really drove home how careful one needs to be with 304 is the realization that its yield strength is similar to hard aluminum or a low strength steel, but after factoring in in tensile necking its ultimate (work hardened) strength is similar to the strongest steels! Thanks for the vid!

[@hdfanboy]

Great video as usual and thanks so much for adding the metric calculations which is super useful for us Australians. Also your new microscope is an awesome addition to your shop it is really cool seeing the swarf up close.

[@jnelson4765]

It's kind of fun seeing other people learn about stainless - my first job was at Greyhound, and those things were almost all stainless. Body panels, frame members, interior components, got real used to being careful around edges. Abrasives work very well with stainless as well - we normally used cutoff wheels for working with sheet metal. Cheap ones would almost evaporate though in the face of the metal - the body shop manager groused about the cost of good cutoff wheels until he saw how many cheap ones we went through :) For me, regular steel in my home shop has been a revelation. 12L14 steel? Holy crap, what a dream compared to fighting stainless...

[@Robbeerrtt]

I graduated jc shop courses 8 years ago. We machined 12L14 for all steel projects. Never saw it again in industry. It's a dream to machine.

[@tysonlamb8114]

Great video J! I'm sure a ton of guys will benefit from this. Always use 303 instead of 304 if you can. Glad I could help.

[@andrewgiles6192]

thank you so much for adding mm alternatives. the way they just appeared on screen as you were speaking was my favourite, as it doesn't take up video time for your US audience, but everyone in Europe can glance and know what you're​ talking about. throwing them on screen during editing is hopefully quick and easy. I'd love to see it continue please

[@Zappyguy111]

Cobalt drill bit. Rubbed a bit on a part, and this little factoid saved the project! Thank you again for all your work!

[@chasenichole813]

Finally someone who has an informative video on this topic! Thank you!!

[@shapezula]

We had some stainless steel pipe at work we were trying to hand drill and we mixed water with baking soda to apply on the bit and it helped tremendously

[@Regalmetalworks]

Yup, I had the same experience as you, melted the 6 flute lsc and gave up. But then I decided to try a rougher and had great results. This is great John! I am putting this in my tool library right away!

[@MrReardan]

The failure attempt looked exactly like mine with the carbide end mill getting orange. Thanks for all the detailed speed / feed settings and tooling information!

[@OldIronRC]

Really enjoying the improvements to the videos with the inlays of the software windows. Great stuff John!

[@mryoutuser]

I Like the metric addition.

[@Yamaprilia]

A couple of points on this subject. Firstly you say not to whisper cut but I work on some bigger jobs that have 0.05mm tollerance on some of the dimensions, you cannot achieve this with a high step over as you get cutter deflection, especially when the tool is long. I have 50mm 304 plate to machine and I have found a way to do the whisper cuts by using 6 flute cutters and by going very slow with the feed and speed and doing 2 or 3 clean up passes. But this takes alot of time obviously. Secondly I am working with haas and ycm machines, they do not offer enough coolant pressure to evacuate chips, alot of people will be in the same boat as me. This means constantly stopping the program to remove chips. You can get air attachments but you need a boss thats willing to buy and install these attachments, of which I do not have! So I recomment breaking up your program into smaller parts so its easier to get to position where you can stop the program to remove the chip buildup.

[@frankmuller5649]

;) Perfect! Thank you for sharing those hints and tricks... awesome video... you even included some metric measurements... thank you for that... your visits to Germany finally seem to pay off! ;) Joking of course... you are great... take care!

[@machinist7230]

Thanks John! I only wish you had put this up a month ago, when we were doing a big job, mostly involving 304..

[@oneworks8013]

Ahhh this would have been so handy a couple of months ago, with metric even! Still learnt a lot from it, machining is definitely one of those "the more you know, the more you realise you don't know" things. One thing my Sandvik rep mentioned that you didn't (you may have heard otherwise?), if you end up going to a carbide drill, don't spot it. The carbide drill should be rigid enough and spot drilling risks chipping the more brittle drill. This video also goes nicely back to your "Twist Drills are AWESOME!" video, because of the shallow ramp angle, drilling a start hole is going to be quite a bit quicker in a lot of cases.

[@nyccnc]

YES - carbide doesn't want a spot! :) SPOT on ;)

[@Wrenchmonkey1]

Can't wait to try this. Pervious attempts have trashed a lot of endmills for me...

[@GeofDumas]

Great info! I have always noticed more resistance with ramping in titanium with 5 flutes but I had never given it a second thought since I do so little ramping

[@chrispalombo6394]

I wish I had seen this last week, before 4 hours of stainless steel nightmare. Ate up all kinds of HSS and Cobalt!

[@madaxe79]

I just found this video after breaking a couple of endmills machining some 304, I've turned heaps of 304 before, but never milled it, This video was helpful, but I found that I had to increase the spindle speed by around 30%, and decrease the feed by around 15% before I could get good cuts and good tool life. this did get me started though.

[@jeffl1356]

Missing your chip break series and updates on your Haas mills.

[@nyccnc]

Stay tuned :)

[@Kugelbolzen]

Thanks for the metric specs !

[@stefanhertweck]

John, great information. Thanks for sharing your tips on how to mill/drill stainless steel.

[@antsman331]

I absolutely love machining 304 and 317. When you get the right speeds and feeds you'll get such a beautiful finish, but it will also let you know when your wrong. About 60% of what our shop machines is stainless and I honestly don't know why everyone thinks stainless is so difficult to machine. I would much rather machine 304 then tungston or tantalum, or even some plastics like rexolite or velspel. Ease in to the material and keep it moving. I use 240-400sfm as my range for milling 35-45sfm for drilling with colbalt. Carbide tsc drills are even more fun and faster! Ever since high-speed dynamic milling was introduced, that's 90% of what I use. Some times I'll go up to 500sfm when roughing. I also form tap all my threads in stainless, unless called out for cut or thin walled, from 000-120 to 1/2-13. And the 1/2-13 went 1.125 deep no problem.

[@CNCGuy]

Im running stainless 304L at .0625 woc, 71 ipm, 390 sfm .250 doc.// 4 flute variable helix AZA Endmill.... Guhring has been back and forth trying to get us good endmills to use, the problem is they dont have the .030 radius like AZA does, they .015 chamfer which chips all the time.

[@greg2337]

@@CNCGuy 5 flute 600sfm 130 ipm 8% stepover. All day long. I cut dry. With such low radial engagement and a chip breaker, BUE isnt an issue

[@CNCGuy]

@@greg2337 what tool are you using? The job I have I only mill .300-.190 deep as a draft angle. My cutter usually lasts about 130parts usually total of 9.minutes in each.

[@greg2337]

@@CNCGuy Helical, SGS, Whisperkut(Sandvik) Lakeshore Carbide. 5 flute EMs are great for SS. Full DOC and light stepover, hard feed puts the heat in the chip. chip breaker shortens the chips and seems to help a lot with BUE. I'm also running it on an Okuma. Ive run a lot of SS on my Tormach 440 but thats where 1/4" EMs really shine.

[@mikewatson5281]

Hello, I have a 6.75 dia x 2.0 thick hog out with a lot of material coming off, is warpage a problem with 304?

[@ScotY808]

Just watched this video again...great stuff! Funny, when I read the description of the 4 flute endmill, I assumed the honed edge meant it was sharper, not rounded over.

[@TuanNguyen-md8cc]

thanks man, i learning mill now. can you do more with other steel and for taping and facing.

[@JamesChurchill3]

Slick editing at 3:06 :)

[@GoKartAlley]

James Churchill yes it was now that you mention it!

[@bobthecannibal1]

That flashback video was painful to see. Looked more like an attempt at friction stir welding.

[@CharlesGallo]

Question on the ramping/VFTS mill. As the issue is ONLY the ramping in (not the pocket itself), why not change your order of operations slightly. Drill your existing hole first, but also drill a start for the pocket, either same size, or if the tool change is fast enough, say a 5/16 drill (or larger to come close to fitting the slot), then going from there. Probably faster than ramping in anyway

[@nyccnc]

Absolutely

[@MaxWattage]

Thank you, just the information I was looking for.

[@winkworks]

Great info, John! Thanks!

[@phucnguyenCNC]

A very good tool. Useful video, very detailed. Thank you for sharing!

[@matthewlennox2488]

I’ve had a lot of success using Lakeshores fireplug VF rougher with stainless running on a 440. I have switched mostly to 416 SS just because of its availability for me and it’s much easier on my tools

[@nyccnc]

YES - 416 ftw ;)

[@jordanhuddleston3351]

Matthew Lennox Care to share your speeds and feeds on your 440 with that fireplug?

[@geminisduerme5266]

First week ever machining 304 and have successfully produced 6 different parts! Unfortunately I broke one endmill and two taps. I dont think thats to terrible just frustrating as heck...this material is not forgiving. Honestly can't wait to go back to machining aluminum...... Wow didnt realize how old this video was lol.

[@chrislane9363]

I love the information in this video. Thanks so much. I have 3/8" solid SS304 that I'm having a hell of a time drilling through. I bought an M42 cobalt set off Amazon, with my makita hand drill on low speel using cutting oil and a 3/16 bit, I made it half way through and it would drill any more. I used up one size and down one size from the set and made zero progress, using plenty of lube and slow speed. I have yet to make one hole successfully through this material and I have many to make! Feeling defeated. I've tried water as cooling fluid to no avail. Tried some hss bits and no success at all. I do notice a bit of a wobble on my drill, almost like the end if the drill the holds the but has a tiny wow or bend in it. Fairly new drill so I don't know how this happened. Could have a negative effect for sure. I simply want to drill 3/16" holes, beveled/ countersunk to accommodate a #12 stainless beveled 1" wood screw into teak. Please, please tell me what I need to achieve this and to do it many, many times over. I have very little garage space but could accommodate a drill press on my work bench if required. These are the bits I purchsed and tried: Metric M42 8% Cobalt Twist Drill Bits Set for Stainless Steel and Hard Metal (1mm-10mm/19pcs) www.amazon.ca/dp/B07MZQMPMC/ref=cm_sw_r_apan_i_0XP1SVWHY5AFBFR2AJ0D

[@mjshorty19]

i had to do 2 18" slots in 304L, .250" wide and .250 deep. total nightmare. Lakeshore tools did not work. Ended up going with Niagara Stabilizer 2.0. 440 sfm, .001ipt - 6722rpm 27ipm. worked great.

[@amareshsethi1211]

Thank u. Plz give some idea to do deep hole drilling on 316 stainless steel.

[@mikewatson5281]

What about warpage when you release it from the vise ? Is that a problem with 304?

[@rebelred1458]

Very helpful. Thanks, John!

[@edsoncarbajal505]

Would the same rules apply when milling with a ball end mill versus the square endmill?

[@MojoMfg]

Is there a specific set screw you use to hold in your 1/4" end mill? Or is it just the one that tormach provides with the tool holder?

[@saledjokic9374]

I would like to ask you what speeds and feeds should I use if my tool diameter is ϕ2? I need to machine irregular pockets 1 mm deep in the same material as you are doing the video.

[@chadkrause6574]

We have good luck with Helical endmills. We can push them pretty hard in stainless. Also turning stainless is a breeze!

[@chillinfinity]

A2 Stainless steel is equivalent to AISI 304 and Lakeshore has A2 listed below the 4 flute endmill.

[@RallyRat]

That may be referring to A2 tool steel.

[@chillinfinity]

You are probably right as they also have D2 in the list.

[@cncit]

Great with the metric comparisons..now I can see clearly again :-)

[@FratDede]

I didn't see any metric comparisons?

[@DavidP_]

do you use the same feed for helical entry ?

[@wahajaleem1579]

hy sir, i am working on steel non magnetic 304 grade. and i am using 6mm endmill with 65 hardness. my work piece depth withh tool is 0.5mm with 40mm square having endmill angle 51 degree with half of endmill. but it work best sometime , and mostly it not works in just good condition. so sir i want some suggestions for it.

[@teroojaranta3639]

Great video and lots of useful information! While ago I asked Sandvik their recommendation of shoulder mills for 316L Stainless. They recommended to not use flood coolant since that causes a great temperature change on the cutting insert. Or at least in my case because operations had lots of interrupted cutting. This causes thermal cracking which destroys insert quickly. I managed to cut 316L just fine without coolant after all. Later I built an cheap DIY air blast for jobs where I cannot use flood coolant but where I need to get good chip evacuation. I cannot wait to get my hand on some mist coolant setup :D

[@WillGarciasv]

So, I'm using a HSS .625 2 flute end mill on aluminum but I just can't find the correct speeds and feeds for it. Help please

[@tj9382]

Good advice as usual 👍

[@bluedeath996]

Is there any reason not to use Cobalt drills and to use HSS on other materials.

[@kokoeohhyeahh7099]

how about ss316 would be nice to know the different

[@What-is-thehandle]

Hey John! How about 303 stainless? I know its more gummy. Maybe a 2 or 3 flute?

[@CNCGuy]

303 is much more forgiving stainless, cuts like butter... At my job, all we run is 304 stainless, so finding the best recipe for speed and quality is important... I have found it. Using AZA Endmill 5/8 flute length, variable helix, 4 flute, 1/2 Dia .030 Radius Very Important to have the Radius, No Chamfers!!!.... .0625 WOC, 71 IPM, SFM 390 or 2979 rpm and .250 DOC. Make sure to use adaptive toolpath strategies. You can do regular, but slow down to 30 ipm in corners where engagement is more than .175 woc

[@clark1ra]

Great video John. Very informative. Don't see it posted...is there a link to get your most recent speeds and feed excel spreadsheet? Thanks

[@andrewgiles6192]

Ray Clark patreon users can access it. it's a low price and supports John do what he does

[@clark1ra]

Yes I do support John through Patreon but four some reason not seeing it there.

[@SuperSecretSquirell]

Did I see the work piece or vise get pulled up at 2:09?

[@skfab]

What I saw was the adaptive tool path is not straight, it moved the work back which made it look like it went up.

[@SuperSecretSquirell]

Ah, good point. Didn't think of that.

[@mbcustomcycles4823]

If it is very difficult avoid work hardening the surface how do you face mill 304? Is cooling enough to stop that..

[@tehfrannjo]

did you figure it out after 5 years :D either use 45 negative cutting edge or 12 positive highfeed cutter with low cutting speeds, we used around 120rpm and feeds up to 1000 for roughing without coolant

[@Smokeslingerowner]

Pilot point is good for hand drilling SS sheet metal.

[@dvn8949]

whats max depth of cut?

[@Tohrak59]

Thanks for the metric!

[@cuprakol]

Don’t forget tapping I always use rolled taps on stainless as your not cutting your forming in st/st 😉😉

[@ianschutt6242]

Thanks!....Stainless doesn’t seem so daunting now.

[@as45454]

Thanks

[@m0dified79]

for stainless 350 sf is what works for me. .003-.005 per tooth

[@seindich1769]

304 cannot reasonably harden - it is austenite. the problem is it dissipates a lot of impact energy and regular tool cant soften it by heat

[@danieltoosi5415]

great tips. thnx

[@bestekengg]

GOOD THANKS

[@Werew564]

Great 😁

[@cyber2526]

"hard to machine and easy to destroy end mills with" ah okay i thought it was just me haha

[@JorgeLuisTorres91]

Why cutting so slow??

[@ginya1102]

Great content. You should do more Glock slides lol

[@samuelbehrendt6291]

I am so spoiled... I have a newer Hurco VMX 64 CAT50 taper VMC with a 4th axis.. i run it every day.. I tried, last night to program a roughing op for a coworker on a considerably smaller CAT40 taper machine.. it wasn't stout enough to handle even 15 percent of the MRR with the exact same tool.. I gotta stop giving these guys so much grief.. we can't all have the multi-million dollar machines.. then again you dont just fall into being trusted with multi-million dollar machines.. they smash them often and I have to fix them lol

[@occamssawzall3486]

Order up some 304 L series and compare the difference between the two. You’ll be surprised at the difference between 304 and 304 L

[@nyccnc]

L is worse, right? I vaguely remember buying some years back thinking that, like 12L14, the "L" meant added "Lead" to increase machinability. That was not the case ;)

[@occamssawzall3486]

NYC CNC way worse. About a 25% reduction in S&F over non L. And even less forgiving. L means “low carbon” which makes it suitable for welding. Non L doesn’t weld as good and the weld beads are prone to rusting. L has about half the carbon of standard series and slightly higher nickel content. 304 (also called 18-8) has usually only 8% nickel where as 304L has 10-12% nickel typically.

[@Bespoke-metal-fabrications]

You probably won't find much difference anymore, not sure about the US but in the UK it is now common practice to dual certify 304l as 304 as most producers apparently go for the lower carbon limit. Check the material cert, you'll probably find that it's 304/304l.

[@occamssawzall3486]

Bespoke Metal Fabrications I could be wrong but I believe European 304L is held to the low end of the nickel content, around 8-9%. Both 304 and 304L can have nickel contents between 8-12%. So you can make 8% nickel 304L. States side 304L rarely dips below 10% nickel. It’s that higher nickel content that really effects machinability, especially in drilling ops.

[@Bespoke-metal-fabrications]

Occams Sawzall Sounds good to me, my Aalco guy is gonna choke on his coffee when I hit him with this the next time he gives me the "... 304 / 304l it's all the same..." talk.

[@GoKartAlley]

Forgot to thank you for this video! We would have never gotten these kennels made without it! kzbin.info/www/bejne/moi5i2p9r9iCZrc

[@sp1nrx]

The next material is A286....LOL...

[@userwl2850]

sp1nrx easy to cut.

[@rogerovitt4570]

So would you say 200 sfm would be a good starting point for most carbide endmills with 304?