Versatile use: Ideal for industrial, commercial, and household applications, from construction to automotive and food processing.

A simple way to think of it is to treat them in a like for like as proportional. e.g. the forces will be the same for cutting twice as deep at half the feed. This is not technically correct as the helix of the tool (flute twist) changes the cutting forces, force direction, and sheer. So if you have a tool with a helix you will take slightly less force cutting twice as deep at half the feed. With stepover you also have the issue of chip thinning. Chip thinning happens when you are taking less than half the bit diameter as a stepover. When you do that you are not cutting the chipload (feed) you think you are. It gets worse the lower you go.

I’m trying to think of ways to speed up my cutting time for a part. I’m using a 1/4" EM. Currently have the DOC set at .1875", feed rate 125 IPM, 40% stepover. My question is - if I change the stepover to 20% or 15%, I should be able to go to .375" DOC and bump my IPM to like 175? I never really see people talking about adjusting stepover, just DOC and feed rates so I wanted to ask.

Surfacingstepover

Depending on material and bit… A 1/4 hogging 1/2" at 100 is feasible with full width cuts… But am extra bit and push the machine till the bit breaks then back off a bit

There are several different materials used to make cutting tools like drill bits, inserts, and milling cutters. These materials have different properties that suit them to different applications. The cutting tool material must be harder than the workpiece material and remain so at the high temperatures generated by high-speed machining. These requirements have led to the development of advanced tooling materials like tungsten carbide that have largely replaced carbon steel tooling, although carbon steel tooling is still used in many cutting applications.

Strong & reliable: Engineered for strength, making it perfect for demanding environments like medical equipment and heavy-duty projects.

Just to get it out of the way, all of the below will first be effected by the tool geometry. Things like rake, helix, edge radius, and carbide grade change all these factors. e.g. like for like a higher rake tool will take less force for the same cut, or a higher helix tool will put more forces into the Z and create more sheer.

In this post, we’ll look at the differences between tungsten carbide vs. steel and other tooling as well as how to differentiate between them when recycling waste metal tooling.

Fortunately, there are other ways to distinguish between tungsten carbide and steel. First of all, tungsten carbide is approximately twice as dense as steel. Comparing the weights of solid tungsten carbide and steel can quickly tell you which one you have.

In general you can increase any of those parameters until you reach the limit of the machine, material, or tool. However, they come at the cost of increased cutting forces and therefore increased tool/machine deflection (bending) even before you reach the limit.

High-speed steel (HSS) is a high-carbon tool steel that usually contains tungsten and other hard alloying elements. It has high hardness, wear resistance, and heat resistance. As a type of steel, HSS is very strong and can withstand high cutting forces without breaking. It is also the cheapest material for cutting tools.

The pass increase is simple as you want to double it. So you are functionally doubling the force depending on helix angle. If we say that it’s decently aggressive maybe only a 90-95% increase. This can also change your engagement time with the flutes. By how much and if it’s an advantage or disadvantage depends on flute count, helix, material, machine, etc.

Versatile applications: From food industry use to complex industrial projects, this sheet is a high performer for all applications.

Currently, tungsten carbide is the most commonly used machining tool material, but other materials and coatings are also frequently utilized. When it comes to recycling scrap metal tooling, it’s very useful to be able to distinguish between tungsten carbide, steel, and other materials, as some are recyclable and some are not. Some materials are much more valuable than others as well.

Industrial Metal Service has been providing San Francisco Bay Area industries with fair and honest metal recycling services for more than two decades. We recycle tungsten carbide tooling and inserts, with no minimums on how much can be recycled at a time. These spent tools can return significant value to your company.

CNC stepoverpercentage

Pine: speed=23000 RPM, feed=250 IPM, ramp feed=100 IPM, stepover=.200", DOC=.200", climb milling. This gives a feed per tooth of .0054" and uses .33 HP. Pine does not cut as clean and you have to be more careful of breaking chunks off - thus the slower feed rate.

Hope that’s useful and is not just a bunch of technical babble. Let me know if there’s something I can expand on or help with.

Tungsten carbide is a versatile, durable chemical compound of tungsten and carbon. In tooling, it is combined with cobalt to form a composite material with excellent hardness, wear resistance, strength, toughness, and heat resistance. Its high hardness and wear resistance are stable at higher temperatures than steel, allowing for faster cutting speeds than steel tooling.

To answer your suggestion of smaller stepover and deeper DOC: I have also tried in walnut: speed=23000 RPM, feed=470 IPM, ramp feed=100 IPM, stepover=.100", DOC=.233", climb milling. This gives a feed per tooth of .0087" and uses .84 HP. This i felt was too aggressive when the cutter was starting a pass and was cutting full width - otherwise it worked fine.

This all probably seems aggressive - and it is because I was getting tired of roughing taking so long. Cutters seem to be lasting longer since they are actually cutting for less time and taking more in each bite. Router is working hard but never gets hot - or even warm at the bearing. I like to keep the RPM high to give lots of cooling. I never leave it alone though with all the horror stories.

Durable construction: Thick, low-carbon stainless steel offers superior strength and excellent durability for heavy-duty projects.

Identifying tungsten carbide vs. steel tooling can often be done visually. Steel tools are usually forged from a single piece of steel, with the tip hardened by heat treatment. Tungsten carbide tools typically consist of a steel body with a tungsten carbide insert. Tungsten carbide is darker than steel, and the joint between the carbide insert and the steel tool body is usually visible, making carbide tools easy to recognize. When these tools fail, it is usually either along this joint or by breaking the tip. However, some small milling cutters are machined from a single piece of tungsten carbide, so the joint line may not always be present.

Stepoverand stepdownin CNC

Let’s use that with some of the examples you have. You are currently cutting with 0.1875" pass, 40% step over, and 125IPM. I need a RPM and flute count for this so I’m going to make them up and say we are at 12KRPM (~800SFM) with a 2 flute cutter.

In general the deeper DOC then the shallower stepover you will need. I like to keep the feed per tooth up close to .010" for long tool life so with smaller step overs that will mean higher feed rates. But you have to be careful of the areas where the cutter will burry itself to full width then it may be too much feed. That is why I decided that .240" wide stepover and .100" DOC was best. The limiting factor with feed then was the HP which I like to keep around .8

Now we need to know what that stepover does to the chipload. So changing nothing else a 20% stepover changes our true chipload to 0.0042" (82% of the original) , and 15% changes it to 0.0037" (72%). The engagement time is different too. I’ll leave that for now though.

We also need the chipload for this so feed / RPM / flutes which gives us 0.0052". If you don’t know, chipload is the thickest part of the chip and without chip thinning, how far forward the tool is moving for each rotation of a flute. This is reduced by chip thinning to 0.0051".

CNCplunge rate

CNC stepoverCalculator

Another major difference between tungsten carbide and steel is their magnetism. If you test a piece of tungsten carbide with a magnet, there should be very little attraction. If the magnet is hard to pull away from the tool, it’s steel.

Tungsten carbide tools are more expensive than steel but are usually more valuable in the long run because they last much longer. Tungsten carbide maintains a sharp cutting edge longer than steel, produces a better finish, and can cut harder materials. It can also withstand higher temperatures and therefore faster cutting speeds than steel.

There are fundamental differences in the chemistries of tungsten carbide vs. steel. While steel is a metal, tungsten carbide is a ceramic material. Tungsten carbide is harder but more brittle than steel, so it can crack or shatter from a strong enough impact.

Meshcamstepover

What about coated tools? TiN-coated tools are easy to recognize by their metallic gold color; however, TiN coatings are applied to both steel and carbide tools, so you may not be able to easily identify the underlying material of intact TiN-coated tools.

Industrial Metal Service has decades of experience and over 1.1 billion pounds of metal sold and recycled. Our founder, Jeff, has spent his life in the industry and prides himself on offering fair, efficient, trustworthy, knowledgeable, outstanding customer service. We offer metal sales, metal recycling pickup service, and other associated services, such as precise metal sawing, machinery teardown, and warehouse cleanup. Give us a call and we’ll get it done. View more posts

Carbide tooling can be improved even further by adding coatings like titanium nitride (TiN). Some of the benefits of TiN-coated cutting tools include:

V bitstepover

Weldable & adaptable: Seamlessly welded for easy fabrication in diverse applications, from appliances to large structures.

I’ll also get the simple ways of getting this done faster. Get a tool with more flutes. Like for like switching from a 2 flute to a 3 flute will let you go from 125IPM to 187.5IPM with the same forces. You can also increase the RPM and feed proportionally if the tool is aggressive enough. These change other things too but you’ll see some of that in the below (if anyone can get through it).

StepdownCNC

Polycrystalline diamond is another composite material that consists of diamond particles sintered together with a metallic binder. Diamond is extremely hard—even harder than tungsten carbide—making it an excellent material for cutting tool edges. Some advantages of polycrystalline diamond as a tooling material include:

Exceptional durability: Built tough with superior resistance to corrosion, heat, and wear, ensuring long-lasting performance.

HSS performs well in intermittent cutting applications, but its maximum cutting speed is far lower than more advanced materials like tungsten carbide. Tungsten carbide tools and inserts have almost completely replaced HSS in most cutting applications. However, HSS is still a popular material for drill bits, as they are less likely to break, especially when drilling deep, small-diameter holes.

I have been roughing a lot of pine and walnut lately with a 2 flute 1/4"EM. Here is what I found: Walnut - speed=23000 RPM, feed=350 IPM, ramp feed=100 IPM, stepover=.240", DOC=.100", climb milling. This gives a feed per tooth of .0076" and uses .84 HP. The cutter will only get up to 350 IPM if there is a straight cut over 1". If there are shorter lines or a lot of curves the actual fee rate will be 50 - 200 depending.

Finally, tungsten carbide and steel spark differently when cutting. If you put them on a grinding wheel, tungsten carbide sparks are closer together and more orange in color than steel sparks.

Usual preface, I’m with PreciseBits so while I try to only post general information take everything I say with the understanding that I have a bias.