{"id":3532,"date":"2026-10-15T13:47:06","date_gmt":"2026-10-15T05:47:06","guid":{"rendered":"http:\/\/www.votonmachinery.com\/blog\/?p=3532"},"modified":"2026-10-15T13:47:06","modified_gmt":"2026-10-15T05:47:06","slug":"what-is-the-relationship-between-cutting-force-and-cutting-parameters-in-cnc-turning-457d-a94cca","status":"publish","type":"post","link":"http:\/\/www.votonmachinery.com\/blog\/2026\/10\/15\/what-is-the-relationship-between-cutting-force-and-cutting-parameters-in-cnc-turning-457d-a94cca\/","title":{"rendered":"What is the relationship between cutting force and cutting parameters in CNC turning?"},"content":{"rendered":"

Hey everyone, it\u2019s Jake from your go-to CNC turning supplier \u2013 and today I wanna talk about something that\u2019s been popping up in our shop huddles, client check-ins, and even the random Slack dms I get at 9pm: the whole link between cutting force and CNC turning parameters. If you\u2019re new to this (or just tired of guessing why your parts come out warped or tools snap mid-job), this is for you. Let\u2019s keep it real \u2013 no stuffy textbook jargon, just what I\u2019ve learned running this shop for the last 8 years, troubleshooting 100+ jobs a month. CNC Turning<\/a><\/p>\n

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First off, let\u2019s cut through the confusion: cutting force is basically how much physical push\/pull the CNC tool exerts on the part as it\u2019s turning. Too much of it, and you\u2019re looking at bent tools, lousy surface finishes, or even the part shifting right off the chuck \u2013 we\u2019ve all been there, scrubbing a $500 aluminum part at 7am panicking. Too little, and you\u2019re wasting time with extra passes that make your order late (we hate delayed orders here, trust me). But here\u2019s the thing: cutting force doesn\u2019t exist in a vacuum. It\u2019s tied straight to the parameters you punch into the CNC. Let\u2019s break this down like we\u2019re hanging out in the shop break room, not in a lecture hall.<\/p>\n

First, the big three parameters everyone messes up at first: cutting speed, feed rate, and depth of cut. Let\u2019s start with the one I get asked about most \u2013 why does changing speed feel like it changes everything? Cutting speed is how fast the tool\u2019s edge is moving across the part surface, usually measured in SFM (surface feet per minute) or RPM (revolutions per minute). A lot of new operators crank up RPM to \u201csave time\u201d \u2013 but here\u2019s the secret I wish I learned sooner: for most materials (aluminum, steel, brass, even plastic), increasing cutting speed doesn\u2019t<\/em> make force go up as much as you\u2019d think \u2013 wait, no, hold on, let\u2019s clarify that. If you\u2019re going super slow on a steel part, the tool kind of \u201cscrapes\u201d instead of cutting, so that\u2019s higher force. But once you hit the sweet spot (we nail these numbers for every material we stock), higher speed actually lowers cutting force a bit because the heat softens the material right at the tool edge, making it easier to slice. But if you go way<\/em> over that sweet spot? Force spikes because the tool starts chipping, not shearing, the material \u2013 we snapped a carbide insert last month testing that on a 1045 steel order, cost us an hour of downtime, never again.<\/p>\n

Next up: feed rate. That\u2019s how far the tool moves along the part per revolution<\/em> \u2013 think of it as how thick each \u201cchip\u201d of material you\u2019re pulling off is. This is the biggest driver of cutting force, hands down. Let\u2019s use a simple example: if you\u2019re cutting a soft aluminum part, a slow feed rate (say 0.005 inches per revolution) makes thin, wispy chips that don\u2019t push back much. Crank that to 0.015 inches per rev? Suddenly you\u2019re taking a thick, heavy chip \u2013 that\u2019s 3x more force, easy. We had a client last quarter who was trying to machine a titanium bracket, kept breaking tools, turned out he was running twice the recommended feed. We adjusted it, tool life doubled, and he finished his order a day early \u2013 that\u2019s the kind of win we live for. One quick note here: feed rate interacts with tool geometry too \u2013 a broad face mill will handle higher feed without spiking force, but a tiny 1\/8\u201d end mill? Feed too high, and it\u2019s like pushing a knife through butter that\u2019s frozen \u2013 no bueno.<\/p>\n

Third, depth of cut. That\u2019s how far the tool dives into<\/em> the part, perpendicular to the turning axis. If feed is how thick each chip is, depth of cut is how wide (well, deep) that chip is. So if you run a 0.1\u201d depth of cut vs 0.05\u201d, you\u2019re pulling twice as much material per pass \u2013 so cutting force is roughly double, too. A lot of new guys try to do full depth in one pass to save time, but on hard materials like stainless or titanium? That\u2019s a ticket to tool failure. We always advise splitting deep cuts into two passes \u2013 0.05\u201d each instead of 0.1\u201d \u2013 and that cuts force by like 40%, plus makes the surface finish way smoother. Last month we had a medical device client needing a deep slot in 316 stainless, did it in one pass and broke two tools, switched to two passes, no issues, part passed all their inspection checks.<\/p>\n

Now, here\u2019s where it gets tricky (and why most online tutorials are wrong): these parameters don\u2019t work in silos. You can\u2019t just tweak feed rate and ignore speed, for example. Let\u2019s say you\u2019re cutting brass \u2013 brass is soft, so you can run higher speed, but if you pair that with a super high feed, force might actually be less<\/em> than if you ran low speed and low feed? Wait, no, let\u2019s test that in real terms: speed of 500 SFM, feed of 0.01 IPR on brass \u2013 force is around 120 lbs. If you drop speed to 200 SFM, even with the same feed, force jumps to 180 lbs. That\u2019s a huge difference, and it\u2019s because the heat from higher speed softens the brass, so the tool doesn\u2019t have to push as hard. We log every single job in our shop software, so I can pull that data up right now \u2013 just last week, a 6061 aluminum part: speed 1200 RPM, feed 0.008 IPR, depth 0.08\u201d \u2013 force was 95 lbs. Same depth, feed bumped to 0.012 IPR, speed dropped to 900 RPM? Force was 150 lbs. So it\u2019s not just individual parameters, it\u2019s the ratio between them.<\/p>\n

Also, don\u2019t sleep on material hardness and tool material \u2013 I know we were talking about parameters, but this ties right in. If you\u2019re cutting a soft, low-carbon steel, you can run higher speed and feed without spiking force. But if you\u2019re working with hardened tool steel (HRC 50+), you gotta slow way down, lower feed, maybe use a coated carbide tool. Last year we had a client who was machining a die mold out of HRC 52 steel, tried running the same speed\/feed he used for 1045 steel, tools snapped in 10 minutes, we adjusted to half the speed and 70% the feed, tool life went to 2 hours, perfect finish. So material is a context here \u2013 cutting force and parameter relationships change based on what you\u2019re cutting, not just the machine.<\/p>\n

Now, what does this mean for you<\/em>? If you\u2019re someone outsourcing CNC turning jobs, not running the machine yourself, this is key for your parts. If you\u2019re pushing for a tight tolerance part with a smooth finish, you don\u2019t want cutting force spiking because the shop cranked feed to get it done fast (we\u2019ve all gotten parts that look like a gorilla machined them, right? That\u2019s usually too much force from bad parameter choices). But you also don\u2019t want them taking 5 extra passes just to lower force, jacking up your price. Finding that sweet spot between parameters is how you get quality parts, on time, at a fair cost \u2013 that\u2019s what we pride ourselves on here.<\/p>\n

Wait, let\u2019s address a common myth I hear all the time: \u201clower cutting force = better parts.\u201d No, not exactly. Sometimes you need a certain amount of force to get the cut right. For example, if you\u2019re turning a thin-walled part (say a 0.1\u201d wall aluminum tube), too little force makes the tool \u201crub\u201d instead of cut, which works-hardens the material and makes it weaker. You just have to balance it \u2013 enough force to get a clean cut, not so much that it bends the wall. We had a client with a thin-walled aerospace bracket, at first their parameters gave 110 lbs force and a bent wall, we adjusted to 85 lbs force, clean cut, no bend, passed their stress test. That\u2019s the balance everyone needs.<\/p>\n

Another thing: chatter. Oh man, chatter is the bane of our shop\u2019s existence, and it\u2019s directly tied to cutting force and parameters. Chatter is that weird, high-pitched vibration that makes parts look like they have ripples, and it\u2019s almost always from unbalanced force. If your feed is too high for your tool or part stiffness, the force spikes, the tool vibrates, and boom \u2013 chatter. We fixed a client\u2019s automotive hub job last month by dropping feed 10% and increasing speed 15% \u2013 force dropped 12 lbs, no chatter, surface finish went from Ra 1.6 to Ra 0.8, which was exactly what their customer required. Small adjustments, big difference.<\/p>\n

Now, let\u2019s get into how we use this in our shop every day. We\u2019ve built a parameter database over 8 years \u2013 for every material (aluminum grades 6061, 7075, steel 1018, 1045, stainless 304, 316, titanium, brass, even exotic stuff like Inconel), we log the optimal cutting speed, feed, depth of cut, and the resulting cutting force. When a new job comes in, we pull the material, part geometry, tolerance requirements, and immediately adjust those parameters to keep force within a safe range. For example, a tiny custom pin for a medical device (0.05\u201d diameter) \u2013 we use a smaller depth of cut, lower feed, because a thin tool can\u2019t handle high force. A large aluminum fixture plate (12\u201d diameter) \u2013 we can run higher feed and depth, because the part is stiff, force won\u2019t cause issues.<\/p>\n

I also wanna mention tool wear here, because it\u2019s tied to cutting force, too. As your tool gets dull, cutting force goes up \u2013 plain and simple. A new carbide insert for steel might have force at 100 lbs, after 10 parts it\u2019s at 140 lbs, which can cause tool breakage or part defects. So part of our process is monitoring cutting force in real-time (we use basic force sensors on our lathes) and replacing inserts before force spikes \u2013 that\u2019s how we keep our defect rate under 0.5%, which is way lower than the industry average.<\/p>\n

Okay, let\u2019s wrap this up with what you actually need to remember, whether you\u2019re a machinist, a project manager, or someone looking to get CNC turned parts made. First, cutting force is directly driven by the big three parameters: feed rate is the biggest factor, then depth of cut, then speed \u2013 but they work together, not alone. Second, material hardness and part geometry (thin vs thick, small vs large) change the sweet spot, so there\u2019s no one-size-fits-all number. Third, balancing force isn\u2019t about going as low as possible \u2013 it\u2019s about getting enough force for a clean cut, without causing chatter, tool breakage, or part distortion.<\/p>\n

If you\u2019re reading this and you\u2019re tired of parts that don\u2019t fit, tools snapping, or jobs running late because of bad parameter choices \u2013 we get it. This is what we do every single day, troubleshooting this exact stuff, fine-tuning parameters to keep cutting force in line, so you get parts that meet your specs, on time, and at a price that doesn\u2019t make you groan. We work with small businesses, aerospace firms, medical device startups, all kinds of clients \u2013 no job too small, no material too tricky.<\/p>\n

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If you\u2019re ready to stop guessing about cutting force and parameters, and get CNC turning done right, hit us up to chat about your next project. We\u2019ll walk you through what parameters we\u2019d use, how we\u2019ll keep cutting force under control, and get you a quote fast. No jargon, no hidden fees, just good work.<\/p>\n

Aluminum Die Casting<\/a> References<\/p>\n

    \n
  1. Childs, T. H. C., Maekawa, K., Obikawa, T., & Yamane, Y. (2000). Metal Machining: Theory and Applications. Butterworth-Heinemann.<\/li>\n
  2. Shaw, M. C. (2005). Metal Cutting Principles. Oxford University Press.<\/li>\n
  3. Stephenson, D. A., & Agapiou, J. S. (2016). Metal Cutting: Theory and Practice (3rd ed.). CRC Press.<\/li>\n
  4. Boothroyd, G., & Knight, W. A. (2006). Fundamentals of Machining and Machine Tools (3rd ed.). CRC Press.<\/li>\n<\/ol>\n
    \n

    Shenzhen Shunhaoda Technology Co., Ltd.<\/a>
    With abundant experience, we are one of the most professional CNC turning manufacturers and suppliers in China. If you’re going to buy bulk high quality CNC turning made in China, welcome to get free sample from our factory. Also, custom service is available.
    Address: 902, Building A3, Tianrui Industrial Park, No. 35 Fuyuan 1st Road, Zhancheng Community, Fuhai Street, Bao’an District, Shenzhen
    E-mail: sales@shdindustry.com
    WebSite:     https:\/\/www.shd-industry.com\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

    Hey everyone, it\u2019s Jake from your go-to CNC turning supplier \u2013 and today I wanna talk … What is the relationship between cutting force and cutting parameters in CNC turning?<\/span>Read more<\/a><\/p>\n","protected":false},"author":156,"featured_media":3532,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[3495],"class_list":["post-3532","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry","tag-cnc-turning-4e90-a9997c"],"_links":{"self":[{"href":"http:\/\/www.votonmachinery.com\/blog\/wp-json\/wp\/v2\/posts\/3532","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.votonmachinery.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.votonmachinery.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.votonmachinery.com\/blog\/wp-json\/wp\/v2\/users\/156"}],"replies":[{"embeddable":true,"href":"http:\/\/www.votonmachinery.com\/blog\/wp-json\/wp\/v2\/comments?post=3532"}],"version-history":[{"count":0,"href":"http:\/\/www.votonmachinery.com\/blog\/wp-json\/wp\/v2\/posts\/3532\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/www.votonmachinery.com\/blog\/wp-json\/wp\/v2\/posts\/3532"}],"wp:attachment":[{"href":"http:\/\/www.votonmachinery.com\/blog\/wp-json\/wp\/v2\/media?parent=3532"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.votonmachinery.com\/blog\/wp-json\/wp\/v2\/categories?post=3532"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.votonmachinery.com\/blog\/wp-json\/wp\/v2\/tags?post=3532"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}