Cutting Speed and RPM on the Lathe and Mill

Proper rpm on the lathe and mill increases tool life and productivity. This lesson discusses how to determine the proper cutting speed for various metals and how to convert that cutting speed to the correct rpm for the tool or part.

[@bubbadoolittle2812]

As far as a clear demonstration, this is the best and most straight forward on KZbin.!!!

[@keithb4007]

This is by far one of the most informative to the point videos I have seen. I appreciate that you kept it simple and showed how it's done. I am new to metal turning and this is a fantastic jump off point!! Thank You!

[@pbc1951]

I copied your comment.... It was so good, so well written.... Thanks... Paul I am new at the Milling machine !!

[@freestyla101]

Yet another video that has taught me something I didn’t know in as many minutes as the number of other videos I’ve watched.

[@CapnCrusty]

I know this is an old video but I just found it and I wanted to thank you for it because this one video has (I believe) solved my premature cutter wear problem. I've been running my tools at way too fast an rpm and have been wearing out end mills much too rapidly. I also am making normal sized chips in steel now instead of a bunch of tiny needles that I'm not sure I'll ever get out of my hands completely. Priceless info for me!

[@TomsTechniques]

Thanks, I'm glad to have you on board. As soon as I get my website up and running, the videos will be better organized and there will be project tutorials to help you learn even more. Tom

[@simpleman283]

I was reading the comments and Wow some people really do come straight from the classroom books and calculator in hand looking for someone to critique. As for the rest of us we do appreciate these helpful videos.

[@Canon060009]

I appriciate your vids, they're so simple, informative and very easy to be understandable. Thank you, Tom!

[@MyShopNotes]

I don't know how many times I have come back to this video. I am a hobbyist and don't use this every day, having these resources is great. I am grateful to you Tom and many others out there providing us this educational material.

[@TomsTechniques]

Steve S Thanks Steve. It's good to hear that the video is being used. Tom

[@stephenwright7065]

Thank you for this! I'm going on 3 years of experience in a tool and die shop (no schooling). We mainly work with tool steel and cold roll steel.

[@coyzee1]

Hello Tom, I'm glad I found your site it's excellent viewing. Thanks for the effort you put into making relevant, easy to understand info for us beginners.

[@danmoreton1788]

I am new to using a lathe and mill and I am appreciative of all information that helps me to gain new skills. It was helpful when you showed the math that determined the relative rpm for various metals. Thank you!

[@TomsTechniques]

Hi Dan, I make these videos for guys like you. It's good to know they are appreciated. Tom

[@lowridingtrucks88]

To tell you the truth i was going to watch it later, but you made it easy to understand and i didn't want to stop watching it. Thank you for taking the time to share your knowledge. I also saw your "square up stock video" and i applied it at work and works great! Thank you Tom sincerely.

[@tyler7074]

I'm so glad you taught me what speed to run my tool.

[@WilliamCooperoverdrive]

I was waiting to see the cutting saw in action! That was a big chunk of steel!

[@177BCardinal]

I've learned a great deal from these videos from Tom. I can now sharpen a lathe bit and run it at the right speed. I've had an old South Bend "Junior 9" for almost 50 years and it's high time I improved my skills. Thx Tom!

[@TomsTechniques]

Good to hear!

[@LongIslandEddie]

Tom, I cannot thank you enough for the compendium of knowledge that flows from this instructional video! Like you, I am dedicated to the art (or science) of manual machining, and usually rely upon intuition when setting speeds and feeds, but you clearly give me a more full understanding of the ratios that work best. Nice to know you Tom, I'm subscribed! Thanks again!!!

[@TomsTechniques]

Thanks Eddie.

[@plainwornout3964]

This is right up there with the most useful info us new hobby machinist could possibly get. THANK YOU!

[@TomsTechniques]

Thanks for watching

[@christopherclark8454]

Thank you..... This is so much fun and Soothing cutting parts and puzzling making accurate pieces ..... I never knew there was a job like this

[@747maran]

Thanks Tom, one of best most informative video for a newbie like me, thanks for the time you put in for these videos

[@TomsTechniques]

Thanks for watching.

[@DFSshop]

Extremely well explained. Any simpler than this just isn't possible Well done, Thank you

[@TomsTechniques]

Thanks!

[@medinacentral]

Great video! Very informative. Thanks for uploading!

[@2007markb]

Thanks for the quick reply. I just subscribed to you last night. I already used the tip on squaring the vise in one pass. Works like a charm!

[@diegorocha6733]

What a good video! Showed me exactly what I needed to know. Kept it simple too. Very nice.

[@bobmorgan7913]

Hi I'm new to the hobby, just bought a mini mill. I worked in a machine shop, over 50 years ago. Always wanted my own machines, have a mini lathe. Enjoy watching all the. videos.

[@TomsTechniques]

It's a fun hobby, Bob. Thanks for watching. Tom

[@gymkhanadog]

Awesome information and very well presented. Thank you!

[@jimmilne19]

Second time through this one. Very informative. I also enjoyed Rex Walters' explanation in the comments which answered a question banging around in my head, "Why four?" Let the sleepy viewers fall asleep: we awake ones are interested in both the how and the why. I'm looking forward to a productive new year and you'll be a part of it. Thanks.

[@TomsTechniques]

Thanks Jim, glad you are enjoying the videos. Tom

[@ralphparker]

SFM =RPM * pi * dia (inches)/ 12. [12 inches per ft]. Pi is 3.141... or just round to 3. Circumference of bit = Pi * dia. so RPM = SFM * 12 / (3 * dia) or SFM * 4 / dia

[@TomsTechniques]

RPM and feed rate determine chip load so yes, it does have to be taken into account. But that's another video. :) It's good to hear that you are getting some benefit from my videos. Thanks, Tom

[@sincarisma]

Thank you very much, the results of my milling have greatly improve after watching your video.

[@TomsTechniques]

+Marco Sandoval That's good to hear. Most people tend to run an end mill too slow because they are afraid to burn it up, but that often results in breakage. Proper rpm is critical. Thanks for watching. Tom

[@arkansas1313]

Tom, very helpful. SFPM is easy to understand by watching your 'show and tell' method! EXCELLENT! Thanks....13

[@TomsTechniques]

Glad to be of assistance.

[@pbc1951]

Great Video !!!! This is by far one of the most informative to the point videos I have seen. I appreciate that you kept it simple and showed how it's done. I am new to metal turning and this is a fantastic jump on point!! Thank You! (Copied from Keith B) Thanks Keith B..... Paul

[@theartman410]

Thank You. Just used my first end mill. Like how you made it easy to understand and follow along. Sure going to save you in my files of help.

[@ronhubbard4663]

Tom, as I've told you before your videos are very informative. Keep 'em coming. Ron

[@gabrielbonannoo]

thank you tom Thats the simplest explanation of cutting speed. Real basic topic I know but the basic things are the most important.

[@ZappninLLP]

Thanks Tom, for this very basic and easily understandable explanation. There are a lot of newbies for whom this is brand new stuff and what is obvious to the experienced machinist may be mystifying to the beginner. Thanks!

[@TomsTechniques]

That's who these videos are made for. It's good to hear that they are helping. Thanks for watching. Tom

[@wiav8r]

Cool tutorial Tom. Reminds me of the way my Dad used to explain things to me as a kid. My Dad was old school machinist. I never took to the trade but love watching all the videos. Puts a smile on! :)

[@TomsTechniques]

Thanks Allen, I'm glad you enjoy them. Tom

[@Shift2Movies]

Tom, thank you very much for this tutorial. I'm sure I speak for many of us who have not commented.

[@Hawk74]

Great video and simple to understand, thank you.

[@conkcat]

Thank you, very concise, to the point, very simple to understand. No stupid over loud or annoying background music or dramatic video shots. I am looking to make my own mill, but was unsure of max spindle speed I needed to do this, you have answered this question perfectly. Now I subscribe and look forward to watching your other videos Thank you sir.

[@TomsTechniques]

Thanks for watching. I'm considering building a gantry type CNC mill myself.

[@TomsTechniques]

Thanks, glad you enjoyed it. Tom

[@mikebetts2046]

Outstanding presentation. Thanks for teaching me a few things.

[@TomsTechniques]

Thanks for watching

[@MrThijsthebest]

Mike better use this: rpm x number of tooth's x feedrate per tooth (0.05. = finishing) (0.1 = for removing material) or use that if u want to bake steel and ur mill

[@gonefishing2012]

Thanks for your wisdom. It really helps.

[@mattgwinner4783]

Tom you are my new best friend, I have looked at the charts and tried to understand the written explanations (few and far between) but you have nailed it on the head. I was completely sold when the impact ran to loosen and tighten the tool holder a man after my own " get it done" attitude, I hate tightening and breaking loose the collets' and you have given me the proof that that is a good idea as well. Thank you so much and I look forward to your other straight forward videos. I realize this is basic to you but for those of us starting it is invaluable. God bless the internet, you-tube, your new website, and you as well.

[@TomsTechniques]

Getting the basics down will pay off in good looking and precise parts later on. Thanks for watching. Tom

[@TomsTechniques]

Thank You. I'm hard at work building a website to help organize the existing videos and new ones to come, so stay tuned. Tom

[@scottburrous2375]

Tom, I got my intro to RPN in 1970 when I started with computers. Most of the guys in the class just rolled their eyes and shook their head. I loved it, made so much sense. It was sometime in the mid 70's when the $100 simple/stupid algebraic calculators came out but no RPN. Got my HP 41CV in 81 along with a few modules and memory. I used the navigation module to replace the multiple books required for celestial navigation. I was going to answer the question.but you beat me to it😊.

[@TomsTechniques]

+Scott Burrous I would be absolutely lost without a RPN calculator. You nailed it saying that it makes so much sense. I' all about the logical approach to solving a problem. Sorry if I stepped on your response. :) Tom

[@RenewTheRWandBlue]

I can't thank you enough Tom for this video! I've been doing some milling for awhile now, just fumbling along. It's been on my mind to learn the proper feeds and speeds to make jobs go faster, and I now know that I have been running my mill WAY to slow. I had no idea you could remove metal that fast on a vertical mill. Thanks again!

[@TomsTechniques]

Be sure to download a copy of my cutting speed and rpm chart from the website (tomstechniques.com). That will save you even more time. Thanks for watching. Tom

[@TomsTechniques]

No problem, glad you liked it.

[@wayneklinkenberg2719]

Awesome video there. I've been going to college training in turning and fitting, but a lot of information has been left out in thin air, making it a little risky. Thanks for the tutorial. Its gonna make life a little safer in the workshop!

[@TomsTechniques]

Thanks Wayne

[@rickhelsel5355]

Tom. Thank you for taking your time to make these vids. I'm just a rookie at this , but am learning fast.

[@TomsTechniques]

Thanks for watching.

[@robcullen9984]

Thanks Tom Was trying to cut a 3mm deep oring groove in a manifold today, got it half done and broke end mill, was running way too slow 1300rpm, after seeing this vid i know i was miles off the speed, will have another crack tomorrow Thanks Rob

[@Baza1964]

Getting my mill working later this week. Thanks for the info.

[@proteuswave]

Thanks for the video! Very informative for someone with two new machines.

[@johngilley3518]

Very informative. I can also hear the air ratchet on the draw rod, I always wanted to try that.

[@TomsTechniques]

I works very well, except the cheap Harbor Fright impact wrench leaks air like crazy. I bought s nice Ingersoll Rand impact wrench for it, but haven't had time to adapt it. Tom

[@TomsTechniques]

Thanks, glad you enjoyed it.

[@RalphRotten54]

The trusty HP reverse notation calculator...had one in college and still use 25 years later. Nice video. Thanks for sharing.

[@TomsTechniques]

+djhoosier Thanks. Bought it in the 80's and it's still going strong. Don't know what I'll do if it gives up the ghost. Tom

[@justlearn1992]

very good video Tom!!! Helped me out big time. Glad I found your videos

[@TomsTechniques]

Thanks.

[@terrycannon570]

Outstanding as usual. Thanks Tom

[@TomsTechniques]

Thanks Terry

[@user-tq3pv6ky9k]

I just wanna say 1000 thank you for your simple information 🙏

[@sixtyfiveford]

Exactly what I needed to know.

[@FredMiller]

Very useful info. Thank you Tom!

[@bangtwister]

Thanks for that. Never understood it until I watched your video!

[@GoldenSim27]

very usefull informative video , getting back into machining after years , needed a bit of study , well explained

[@MarkWesley]

Thanks Tom! Very informative.

[@rhysevans6659]

Very useful for my report on the milling process, thanks!

[@TomsTechniques]

Thanks for watching

[@noecortez8677]

thank you tom for such a helpful video great job and easy right to the point

[@TomsTechniques]

Noe Cortez Thanks for watching!

[@TomsTechniques]

You bet Earl, thanks for watching them.

[@sergio05]

Very informative and well made thanks for the tips!!

[@TomsTechniques]

***** Thanks for watching.

[@kensendelofski3761]

very informative. Just getting started in milling.

[@SlowEarl1]

another great video thanks for making them.

[@TomsTechniques]

Thanks, I'll add that one to the list. Tom

[@bomataralshamsia4007]

It’s a very good new knowledge that I got today thank you bro 👍🏻

[@woodywoods5373]

Thank you I learned quite a bit it's exactly what I wanted to know.

[@jackotoole2265]

For metric multiply the cutting speed by 25.4 , surface mm per minute. eg mild steel = 2540 , and use the same formula. 5/8" = 15.875mm 4* 2540/ 15.875 = 640 rpm. Some rounded off number for the other metals. Tool Steel 1800 Cast Iron 1500 Aluminium 6400 Brass 7500

[@StepSherpa]

+Jack O'Toole metric cutting speed is measured in m/min. The formula for figuring out the rpm is (cutting speed x 1000)/(pi x tool/workpiece diameter)

[@jackotoole2265]

+Espen Andre thanks, I agree, the above is just a means of using a cutting speed quoted in feet per min with metric sized tools. Tom has a simpler answer which I overlooked before. cutting speed fpm x 100/ tool size mm

[@TomsTechniques]

+Jack O'Toole I meant to post that in the video but completely forgot. Guess there's no time like the present. :) Tom

[@thomaswilley1956]

Toms Techniques a

[@thomaswilley1956]

Toms Techniques a

[@brianb5779]

Love all the info you put out

[@TomsTechniques]

+Brian B Thanks Brian. I'll try to get some more out over the next few days. Tom

[@jster1963]

Great info, thanks!

[@dobers100]

Thanks for the video...huge help.

[@dannykrumpton4467]

Thanks Tom, cut a new bit today very slight rake and used air for coolant , back gear on the BP little faster on the travel speed , all went well .

[@TomsTechniques]

Good job.

[@TomsTechniques]

Thank you David.

[@jameb5497]

Great info delivered very well! Thanks!

[@TomsTechniques]

Thanks for watching

[@AeroSport103]

Good video! Thanks for posting... Take care, be safe!

[@TomsTechniques]

Great! That's good to hear.

[@ricklonetti9587]

Awesome video! Thank you!

[@TomsTechniques]

Chuck, I'm not a big fan of carbide in the hobby machine shop, so all of my cutting tool videos will be HSS oriented. To answer your question, carbide is generally run around four times the cutting speed of HSS and at much higher feed rates. Well beyond the capability of most hobby type machinery. I will be covering feed rates in a future video. Tom

[@trp3141592]

Thank you for this clear explanation. I have printed out a chart of the cutting speeds and the rpm formula. My antique Vernon Mill has no electronics, so my first task is to measure the rpm of the spindle for every belt setting. With that info I can set my rpm to fit my bit and material. Thank you again!

[@TomsTechniques]

It's good to hear that the material is getting used. Thanks for watching! Tom

[@havebenthere]

I seem to be under speeding most times, then I gradually speed up in following cuts. I never break an endmill but I take to long. Sometimes I don't have a clue what type steel I'm cutting, Hence underspeeding. I've always watched the chips to get a feel for the cut. Thanks for the videos, I'm picking up alot!

[@TomsTechniques]

Too slow an rpm is quite common, but it does waste time and increase tool breakage. There is nothing wrong with going by the color of the chips and feel of the cut, the formula just gets you in the ballpark. Thanks for watching! Tom

[@clarkstevens2711]

OMG thank you for some good information for a change it was very educational I've been looking on KZbin for days trying to come up with what you just told me

[@TomsTechniques]

Thanks for watching!

[@jd4846jd]

great subject matter, well explained.

[@JF_Projects]

Great video, very informative for a starter in metal working like me, I like your channel...

[@TomsTechniques]

+JF- Knives Thanks for watching

[@TomsTechniques]

It's actually a DoAll mill. When I bought it in the 80's, the Bridgeport/Textron mills weren't the quality they once were.This one has served me well over the years. Tom

[@62346]

.....another good one Tom! Thanks!

[@ItsSuperBadass]

I'm really enjoying your videos and learning alot :D One question tho, would the feedrate of the tool effect anything?

[@ramirocortez6392]

Thank you sir ! I burnt up a 1/8 endmill today because my journeymen toolmaker told me to run at 800 rpm !???? Thanx again I am a apprentice toolmaker will be watching you're videos!!

[@TomsTechniques]

Not sure what you were machining, but 800 rpm is about a quarter the rpm you should have been using for mild steel. Was the material hardened by chance?

[@ramirocortez6392]

@@TomsTechniques no 8620 basically cold roll

[@shredder60]

This is an outstanding video Tom thanks for this.

[@TomsTechniques]

Glad you liked it. I just realized that I never posted cutting speed chart on my website. I've been working on it and it will be available in the reference section shortly. Tom

[@shredder60]

Toms Techniques This type of info is what I and probably alot of other noobs are looking for.all the calculations and what there for.

[@transistor754]

Thank you! As a hobby fitter/turner, it gives me a starting point. The rest is up to me to feel the feed rate.

[@andyc8454]

Great explanation thank you!

[@ujjwalkumar4912]

awesome and mindblowing practicle sir,

[@gandaya900]

Good video! Hands on the job!

[@johnbarnwell400]

Thank you sir this was very helpful to me !

[@391dave1]

Great video. Thanks

[@iiinsaiii]

Great videos

[@caribeprepper]

Great Video, Thank you.

[@TomsTechniques]

Thanks for watching