Are you interested to know about the tools used to ensure that modern manufacturing gets a high level of precision and efficiency? Then it’s time for you to learn more about milling cutters, the fascinating and versatile cutting tool capable of shaping metal in the same way an artist’s brush helps the artist create magnificent artwork.
In this article, you will learn about the different types of milling cutters, what makes each machine tool unique, and the things they do to revolutionize modern manufacturing industries. It is time to give the spotlight to these incredible marvels of engineering.
What are Milling Cutters?
Milling cutters refer to rotating tools that you can widely use to perform milling operations. These tools feature at least one cutting edge and are mainly used for machining plates, forming surfaces, grooves, steps, and cutting edges and workpieces.
A milling cutter plays a major role in the modern manufacturing industry because it significantly improves machining performance. As far as a profile milling operation is concerned, your chosen tools will play a significant part in attaining your desired efficiency and precision.
With that said, it’s a must to look for the best milling cutter that will serve as your partner for all your manufacturing, machining, and engineering projects. With this cutting tool, you can cut through all kinds of hard materials, thereby creating your preferred shape and raising your confidence as you tackle even the most complex tasks and projects.
How is the Milling Cutter Used in Milling Machines?
Milling cutters are employed by milling machines to get rid of material from workpieces, which can then create your preferred finish and shape. Expect the cutting tool to rotate while the built-in teeth or cutting edges engage with the workpiece. This can generate chips and eventually produce your desired cutter’s shape and form.
Aside from the straight teeth that can take out material from any piece of stock to create parts and components with more complex shapes and features, there are also milling cutters capable of deburring parts. These tools can mill both external and internal chamfers on parts.
You can also find milling cutters capable of forming tapered grooves or dovetail slots in a workpiece. Some of them can make grooves to mate keyed areas to the shaft.
What’s great about milling machine tools is that they have the capacity to handle one or more cutters simultaneously, thereby speeding up the process of cutting edges and forming your preferred shape.
What Are the Types of Milling Cutters?
The versatility of milling cutters also remains unquestionable, especially if you consider its numerous uses. You will find this milling bit cutter really useful in a lot of operations, including facing, profiling, pocketing, slotting, and contouring.
The efficiency of milling cutters, though, will depend on the suitability of the specific type of tool you have chosen with your current project. With that said, it is important to learn about the different types of milling cutters, so you can better decide which one fits your project the most:
End Mill
End mills are milling cutters with cutting teeth on both sides. This means that this cutting tool features straight teeth on both the periphery and the end face. Aside from the variation that features cutting edges on two sides, which is also called central cutting, you can also find another variation called non-central cutting edge.
This center cutting variation features cutting edges only on a single side. One reason why many people like this center cutting tool is that it is highly versatile, making it useful for several drilling operations. Expect to see end mills being used in plunging, slotting, ramping, and profile milling process and operations, too.
Another thing to note about the end mill is that this particular term is often used for tools with flat bottoms. An end mill is different from a drill bit, too. The reason is that the drill bit cuts only in the axial direction.
Meanwhile, the end mill often features at least one chip removal slot, making it ideal for use in a wide range of milling projects and operations. You can also see it being constructed out of hardened material or high-speed steel.
Face Mill
A face mill is another milling cutter, which you can see being used in a lot of industries. One noticeable fact about this face milling cutter is that it has one cutting body with a large diameter as well as multiple mechanically fixed blades.
It has a cutting stroke along with narrow axial cuts that can effectively take out a huge number of unwanted and hard materials. Moreover, it has a body with an outside diameter that is greatly dependent on the workpiece’s length and the clearance that’s currently available on two sides.
You can use this famous face milling cutting tool when it comes to profiling milling operations. The tool is also popular because of its rigidity. Moreover, it can produce a surface finish and can cut axially, which greatly depends on the tool’s number of teeth and its feed rate.
T-slot Cutters
There is also what we call the T-slot cutter. Also called a woodruff cutter, this T-slot milling cutter works as a specialized kind of milling tool that you can use in creating T-shaped keyways or slots in a workpiece.
This cutting tool actually got its name from William Woodruff, its inventor, who was also famous for developing the Woodruff key along with the cutter linked to it. One of the features of this tool is its specific cylindrically shaped body. It also features a distinctive cutting-edge profile.
It is this tool’s cutting edges that also boast of a T-shaped groove capable of matching the preferred woodruff or T-slot keyway’s dimensions. With the aid of the T-slot cutter design, inserting various fasteners or T-nuts into the slot is possible, which makes you take advantage of T-shaped slots.
Ball Cutter
Also called ball nose mills or ball end mills, the ball cutter got its name because of its hemispherical cutting ends. These ball mills are mainly used to lessen stress concentration when it is still in operation.
The ball cutter works well if you plan to machine 3D (three-dimensional) surface shapes. Its goal is to keep a corner radius, especially when it comes to perpendicular faces.
Slab Mill
You can also use the slab mill for a lot of machining projects. Basically, slab mills refer to large milling cutters with flat bottoms. These tools can be used to machine large flat surfaces or to make wide cutting slots, particularly those that need consistent cutting width.
One fact about slab mills, though, is that they are not commonly used in modern CNC machining centers. The tool is more compatible with manual milling tools, especially when the job involves machining big surfaces quickly.
This is probably why people often refer to slab milling as surface milling. Expect it to work with its slab spinning horizontally between the support and spindle.
Side-and-Face Cutter
Otherwise called shell end mills, the side-and-face cutter features cutting teeth in both the face and side, which makes it suitable for face milling and peripheral operations. It is very helpful for certain tasks, like milling shoulders, facing big surfaces, and machining profiles considered complex.
The side milling cutter is a type of milling tool with cutting teeth present on both the periphery and the face or end. It is typically used for milling operations on the side and face and cutting grooves. They are also effective in creating deep and narrow grooves.
As one of end mill’s predecessors, side-and-face cutters feature more teeth surrounding their circumference and on one side. Such functionality makes it quite similar to end mills, although the popularity of the latter declined due to technological advancements.
Involute Gear Cutter
An involute gear cutter is also a good choice of cutting tool as it is simple yet highly precise. This high-precision tool can help cut helical, bevel, or spur gear. Considered the oldest and the most often used gear cutter, the involute gear cutter will likely cut a wide range of gear from the entire rack depending on the number of teeth that require cutting.
It can also cut gears in all forms of ordinary gear milling machines because of the simplicity of its cutting process. Another fact about this gear cutter is that it is highly durable while being cost-effective. This is the reason why it can cut items on the milling machines one after the other, especially for finishing and roughing purposes.
With the help of this cutter, you can machine gears on your milling machine, whether it is a manual or a CNC mill. Just make sure to match the gear cutter to your gear specifications to get your desired result.
Fly Cutter
This particular milling cutter resembles the face mill in terms of function. Basically, the fly cutter features a central body, which is what holds around one to two tool bits. The ones featuring two tool bits are known as the double end fly cutters.
Another noticeable fact about the fly cutter is that it features a single cutting edge only along with an insert. Despite that, most fly cutters are still beneficial as they can produce fine finishes with the least consumption of power. This causes the tool to operate at lower cutting and rotation speed, though.
In terms of cutting speed and quality, the face mill is also considered better compared to the fly cutter. Still, many choose the latter because the quality is still reasonable plus you can get it at a much affordable price. It can also truly get rid of the rough finish.
Roughing End Mill
Otherwise called rougher, the roughing end mill refers to a kind of milling cutter, which is made specifically to remove huge amounts of material efficiently and quickly. The primary use of this tool is for roughing or doing preliminary machining operations. The goal of such operations is to eliminate the bulk material instead of getting a fine finish.
It is quite the same as the end mills, with a bit of difference: the roughing end mill comes with jagged teeth. This is the reason why it can cut faster compared to the standard end mill. It also has the capacity to remove material swiftly.
It also has smaller cut bits of metal than what’s usual. With that, you will never have a difficult time clearing it up. The roughing end mill also operates with its multiple teeth that come in direct contact with your workpiece simultaneously.
This is a good thing as it can lessen vibration and chatter, which may be worse otherwise due to the presence of jagged teeth. A roughing end mill is specifically useful if you plan to machine big workpieces, prepare them for finishing, or get rid of excess materials.
It is constructed to handle tough materials, including cast iron, steel, and other alloys known for their superior strength. If you wish to invest in a roughing end mill, consider crucial factors, like the type of material, preferred removal rate for the material, and cutting conditions.
Consider the capabilities of the machine, too, so you can attain effective and efficient roughing operations.
Dovetail Cutter
You also have the option to use the dovetail cutter, which is a specialized milling tool for forming grooves or slots shaped like dovetails. These grooves or slots also feature precise angles.
This tool got its name from the dovetail joint popularized by the interlocking wedge-like shape. It is a big help when it comes to mating surfaces or making dovetail joints that need highly precise interlocking profiles.
When it comes to choosing the most suitable dovetail milling cutter for your project, you have to consider crucial factors. Among these are your preferred angle for the dovetail, cutting conditions, unique application requirements, and the properties of the material.
Tips for Selecting the Right Mill Cutting Tool
Choosing the best mill cutting tool is essential if you want to obtain your desired machining result. Note, though, that choosing the best milling cutter is not that easy. You have to consider several variables and factors.
The most essential thing to focus on is looking for a tool guaranteed to help cut the material according to the recommended specifications without spending too much money. The job’s final cost will actually be the combination of the tool’s price, the time it took for the milling machine to work, and the time spent by the machinist.
To help you choose the right milling cutting tool, here are some tips:
Check the material
Milling cutters are constructed from different materials, so it is important to get to know more about what a specific tool is made of before buying. You can find those made of regular carbon steel, although, many don’t prefer this material because it has limited capabilities.
If you are looking for a cheaper cutter, then go for one made of high-speed steel (HSS). It is not that expensive plus it has better capabilities compared to other common materials. You can also choose cobalt-bearing HSS, which is perfect if you want faster milling. This advantage makes the high-speed steel bearing cobalt ideal for most projects.
Another option for the material is cemented carbide. It assures you of a high-performance milling process plus many consider it a cost-efficient choice. Be aware that its upfront cost is higher compared to the rest, though, but you will definitely earn great returns from your initial investment once you start seeing its excellent performance.
Consider the diameter or size
It is also crucial to pick a tool with a diameter or size that perfectly suits your project. In most cases, larger milling cutters can take out material faster than smaller ones. With that said, it would be better to pick the biggest cutter possible, which can fit your chosen job or project.
If you are milling concave external contours or internal contours, it is highly likely that there will be limited diameter based on the internal curves’ size. In that case, remember that the cutter’s radius should be either equal to or less than the smallest arc’s radius.
Check the flutes
Another key factor to check and consider is the number of flutes. Note that you are allowed to have a higher feed rate if you have a higher number of flutes. The reason is that each flute will remove less material.
However, due to the increased core and large diameter, you will also encounter minimal room for swarf, which is why you have to choose a balance.
Examine the coatings
Another important component or factor in the milling cutter that you have to check thoroughly is the coating. Note that coatings, like titanium nitride, can increase the amount you will spend initially while reducing tool wear and increasing the tool life.
It would be best to go for a titanium nitride coating since it can minimize the risk of the aluminum sticking to the tool. With that, you can definitely minimize or even prevent the need for lubrication.
Consider the helix angle
Another important factor to consider before making your choice of a milling cutter is the helix angle. It would be ideal to go for high angles if you will be handling soft metals as such an option is suitable for that. Meanwhile, low angles work ideally for tough or hard metals.
Conclusion
There are really so many things that you can do with milling cutters. It is a huge help for CNC machining as they can shape, cut, and remove material from workpieces. Whether the job requires CNC prototype machining or you need to do large-scale production, choosing the correct kind of milling cutter can assure you of high precision.
Investing in the right kind of milling cutter can also give you a high-quality finish and superior efficiency. That said, you should work on gaining a much better understanding of this tool’s types, milling applications, and features, as this is the key to making a sound decision and choice when it comes to CNC machining.