Endmills are undoubtedly an important part of the mold-making industry. If you are in this industry, you might have heard or known about the end mill tool.
Endmill cutting tools are the necessity of the industrial milling process. These tools have cutting surfaces, commonly known as flutes, that define how refined the cutting process should be and the end product.
The highly automated end mills are a flexible machining process that can produce almost any size and shape. End milling usually differs from the other processes due to the tolling type for cutting the materials.
However, many people are pretty confused with this tool as they usually ask which endmill can do the best job? What are the best endmills available in the market? How to select the best end mill for stainless steel and aluminum? To answer all these questions, we have outlined how this tool works, what end mills are used for, and how to choose affordable end mills.
But first, let’s discover what the end milling is!
What is End Mill?
End milling is a type of process that can be used to make the shoulders, slots, die cavities, profiles, contours, and other milling parts. The milling process uses the endmill cutting tools, which are cylindrical with multiple cutting edges on both its tip, offers the peripheral cutting and permitting end cutting.
Endmill and various cutting tools can be made from a materials host such as high-speed steel (when a special shape tool needed), carbide inserts (suitable for the high production milling), diamond inserts (provide the tight tolerance), and ceramics inserts (for high-speed machining with the high volume).
Solid carbide and high-speed steel (HSS) are the two most common materials by which the endmills are made. The endmill is used to cut the manufacture milled parts for the board applications, including sign making, circuit boards, jewelry, circuit boards, wood engravings, etc. The endmills are available in the flutes, diameters, and flutes.
What is an end mill used for?
Endmills are functional tools used for sculpting holes or shapes into hard surfaces. These robust bits are designed for drilling, reaming, profiling, contouring, and more operations. One can use the end mill tool to cut a wide range of materials through its cutting teeth on the body and face.
These high-performance end mills are available in a large selection of sizes or dimensions. Their style and application depend on the type of endmills you are using. Slightly confusing, right? Don’t worry, we have got you covered.
Our quick guide will take you through everything you need to know about these excellent tools, from end mill types to applications. So, without further ado, let’s get right into it!
How do End Mills Work?
If we see the history of cutting materials, we may get to know that they exist for thousands of years. No matter if by machine or hand, the materials have been crushed or grounded to make a large variety of products. The process has been known as milling since the 1800s.
However, nowadays, the milling process is automated, as mentioned above. The drills and manufactured rotary cutters are attached to the huge milling machines and omit the material from an available workpiece.
Due to the limitless selection of the milling ends and varying drill bits, the milling process can produce nearly anything, including the circuit boards, jewelry, gun parts, and much more.
Different milling processes have been developed in today’s milling industry using different tools and milling techniques. One such versatile process is “End Milling.”
The end milling is quite different from the other milling processes because of the tooling type used for cutting the different materials. The endmills have teeth cutters on the sides and end, unlike the other traditional drills and cutters.
End milling applications are countless, as they are used in tracer milling, face milling, profile milling, and plunging. For unique or non-traditional applications, the CGS tool is specialized in designing custom carbide end mills.
Endmills or any milling cutter are usually used in the CNC (Computerized Numerical Controlled) machines. The specialized software embedded in the CNC machine usually sends a tool path or automated milling instructions to the CNC machine, which then cut’s away a design in the work-in-progress material.
The mold manufacturing market has recently filled with the mini milling machine, tabletop, CNC routers, and exciting top. The CNC routers are now in-expensive and affordable, which let the Industrialist freaks use the high precision tool for engraving and carving.
There are two types of milling cutters available in the market: the drill bit and endmill. But people usually get confused about why to use the endmill over the drill bit? People prefer the endmill because the drill bit movement is up and down, and the endmill moves side by side, making the process easier.
Endmill works seamlessly and powerfully to cut/shape materials. Here are the functions and benefits of high-performance end mills:
- Endmills are accessible in a huge variety of diameters, measurements, kinds, and flutes. They are selected based on the finishing surface required for the project and the material they are cutting.
- Endmills are the king of the milling world and can be used for slotting, contouring, reaming, and profiling.
- They are perfect for cutting the parts precisely like jewelry designs, machine parts, sign making, wood engravings, circuit boards, and mold making.
What is End Mill Made of?
Most end mill materials are either solid carbide end mills or made from cobalt steel alloys, usually known as high-speed steel. The material you will select will depend upon the machine's maximum spindle speed and your workpiece/material's hardness.
● Solid Carbide Endmill
The solid carbide endmills offer no matched cutting performance, high process security, and long tool life for the security process to demand the production parts in the industry segments such as medical, aerospace, power generation, and mold & die.
The quality is exceptionally high, and production is low cost, resulting in these endmills' advantages to come as a guide of a dedicated micro-grain carbide structure in the specialized edge honing optimized flute lengths and wear-resistant coatings.
This endmill is significantly rigid, harder, and more wear-resistant than the others. The carbide end mills are used for high-speed applications and extremely heat resistant on some of the firmest supplies, for example, non-ferrous, cast iron, alloys, and plastics.
● HSS End Mill
The newly developed Ag coating and high alloy HSS achieve the optimum balance of the toughness, wear resistance, enabling high-efficiency machining and chipping help. This endmill delivers stable performance in heavy cutting, and it’s suitable for side milling and pre-finish grooving. The HSS endmill comes at an affordable price but doesn’t provide the speed capacity and tool life like the carbide end mills.
What are End Mills Used For?
Endmills are used for making the holes and shapes during the reaming, making shapes, profiling, milling, drilling, and slotting applications. They have a design like cutting teeth on the edge of the whole body. Plus, they cut the material into various designs.
· Endmill for the Aluminium
The two-flute end mills are used in aluminum and wood. These flutes are the best for keeping this material a bit chiller and finest for keeping the evacuation a bit cooler. Still, it leaves the rougher cut.
Two- Flutes endmills are the best for aluminum and wood materials as these produce huge chips compared to the other different materials. These flutes endmills are also compatible with the slot drills and ideal for the profiling, cutting slots, aluminum, and wood.
Conventionally 2-flute end mills are the faultless choice for aluminum. But, the 3 flute end mills also compatible with Aluminium. The 3 flutes are more fruitful in finishing the materials, and with the correct strictures, they can also work successfully as roughers cloth.
For the tougher material like steel or other harder material, the 4 flute endmills are compatible. The 4 Flutes are not just the perfect endmill for the stainless steel, but they can also create a smoother finish on the other tough surfaces.
What’re the different types of end mills?
As mentioned, there are various types of endmills whose application and use depends on their shape. While some are used for plunging, others are applied for grooving requirements. Here are 5 of the most common end mill types:
Ball Nose End Mill
What is a ball nose end mill? The Ball Nose End Mill is sometimes also called ‘Ball End Mill.’ This is because they have a rounded tip and are available in both single & double-ended variants. While they can be used for conventional purposes, they also have applications in certain high-performance geometries.
These can be used for milling corner radius of larger sizes, profile milling, and even contouring. Ball Nose End Mill with a smaller diameter can also be used for 3D tooling and engraving tasks. One can also use these for slotting and pocketing the surface. These are generally used in mold and dies machining.
Flat End Mill
What is a flat end mill? If you have any task related to cutting shapes in 2D or roughing, then the Flat End Mill would be your best “bit.” These can also be used for engravings and flat-sides 3D figures. These high-performance carbide end mills can easily cut through the wax, wood, plastic, and even metal.
These types of end mills are used to carve flat surfaces with no scallops. If you use these on non-flat areas, they might leave terrace-like scallops on the surface. In such cases, using a Ball Nose End Mill turns out to be a better option.
Corner Radius End Mills
The following end mills type is the Corner-radius end mills, which are also called Radius Mills. These sport a square nose that has slightly curved edges or corners. This helps the bit distribute the force evenly through the bit, reducing the chances of damaging or chipping the endmills.
Generally, these are used for deep milling into a pocket. Or it can also be used to mill behind apart. The Corner-radius endmills with a larger radius are industrially called “BullNose.” Before using these, one has to keep the shape and size of the tool in mind. This will help get the best results as this bit has a longer life than traditional square mills.
Roughing End Mills
The Roughing End Mills are used for getting rid of large quantities of metal in a short span of time. It is a more efficient option for such applications than any other end mills type. Their unique tooth design delivers a rougher finish and renders none to less vibration level. Although, this also depends on the end mill material.
These are also called Hoggers or Ripping Cutters and can be used for deep or large operations. From chipping to slotting, they can do everything reasonably easily. If you get a fine tooth roughing end mills, then remember they will permanently remove lesser material at the same time. However, they are more lasting and durable than the basic ones.
How many flutes does an end mill have?
Flutes are the valleys or grooves present on the tip of the endmills. They are one of the most basic and easy to identify parts of any end mill cutting tool. These spiraling grooves support the shaping and removal of the material. In more straightforward terms, flutes help the end mill tool to cut into the provided surface.
The more the flutes, the higher the tool strength. It also reduces the chip flow or spacing and can be used to cut into harder materials. On the other hand, end mills with fewer flutes will have higher chip space. Now that we have covered what are flutes, here are the flute types available in high-performance end mills:
2 Flute End Mill
Regardless of the task, a two-flute end mill can be used for everything. While you get a higher flute volume by using these, they deliver slower feed rates. But, these are great for chip removal tasks while grooving. The 2 flute end mill is available in a wide range of sizes.
You can find any mill you need in the market, from extra long to small stubs. There are also micro-end mills available in 2 flute options. These feature an end geometry of corner radius, square, or ball endmills. Besides, they also render higher chip carrying capacity.
The 2 flute end mills are mainly used for pocketing or slotting nonferrous materials. These can also be used for tasks related to grooving. Sometimes, these are used for digging deep vertically into the surface. This has given it another name- ‘Plunge Mill.’
At the cutting tip of this bit, you will find two different blades of unequal lengths. One is placed straight across the middle, which helps it in cutting directly into any surface. Furthermore, you will also have to remember that these bits cannot be used as replacements or substitutes for other bits.
3 Flute End Mill
The next name in types of endmills based on its flutes is the 3 flute end mill. Rendering higher feed rates, these are most commonly used in aluminum machining. One can also use these for grooving tasks with crowded chips. Another application of these bits is in non-ferrous milling.
The design of the 3 flute end mills is very much similar to the two flute end mills. But they have a bigger cross-section, which helps in delivering better strength. It can be used for slotting both nonferrous and ferrous materials. These bits are known for delivering lesser vibrations during cutting and engraving tasks.
4 Flute End Mill
If you are looking for endmills for side or surface milling, then the best option is the 4 flute end mill. These mills' effect and output are very much similar to the conventional 2 flute carbide end mill. You can also use these for pocketing and slotting tasks.
The faster feed rates of four flute end mills help in delivering higher feed rates. However, the only drawback is that these cannot be used for chip removal or grooving tasks because of lower flute space. Contrarily, they work impressively in giving a sleeker finish. This makes 4 flute end mill a better option for finish or peripheral milling.
What is the difference between a 2 flute and 4 flute end mill?
We have mentioned above that 2 flute carbide end mill, and 4 flute carbide end mill is quite similar. The 2 flute mills are perfect for performing tasks in enclosed spaces. However, it would not be the best choice for tasks that require a lot of strength.
The design of two flute end mills is perfect for milling tasks. Moreover, the more flutes your bit has, the higher the feed rate it will deliver. This makes the four-flute end mill a better option for finish machining. One can also use these for mining hard resources like aluminum.
Since the chip removal space is higher in the 4 flute mills, the bit does not stick to the cutter easily. The chip removal can be done easily if you have a bit with a lesser flute count and the chip holding groove is bigger. But, if the end mill tool is less rigid and the cross-section is tiny, its body will bend while performing cutting-related tasks.
You can enhance your end mill cutting tools' rigidity by increasing the cross-section area and flute count. Although, this would mean that you will have a smaller chip holding groove. Thus, reducing the holding force, which can cause chip blockage. It will also affect the surface finish of your workpiece.
But, if you get a shorter flute, you can have enhanced tool cutting performance. It will also increase the rigidity of your end mill tool. Always remember that the 3rd power of edge length would always be inversely proportional to the mill’s rigidity. Therefore, if you double the flute length, your tool’s rigidity will reduce by 1/8 of its initial strength.
Difference between a drill bit and an end mill
From material milling to CNC functioning, high-performance end mills are used for a variety of tasks. The main application of these bits is to remove the chipped material. While these look strikingly similar to traditional drill bits, they are more multifaceted than the latter.
Moreover, people sometimes use bits instead of endmills to describe these tools. There are substantial differences in performance and application of the drill bits and end mill cutting tools. Drill bits are used to create cylindrical holes, axial cutting, or plunging into the surface.
On the other hand, high-performance carbide end mills are generally used for lateral or horizontal carving. This is mainly because most endmills have a center-cutting feature. It means that you can use these to perform axial and lateral cutting easily.
The cutting flutes present on these different end mills allow the user to plunge and easily cut into the surface. If used with CNC software, you should focus on using the endmills to make slow lateral cuts. This will reduce the chances of tool breakage.
There are various other aspects on which drill bits and endmills are differentiated. Check out some of these differences below:
Applications & Shapes of the Tip
As you have read above, there are different types of end mills with varying applications. The tip of every drill or end mill tool is designed for a particular purpose.
From flathead to ball nose end mill, each has a different design and use in the industry. Endmill bits are used for numerous tasks, ranging from milling to 3D contouring. On the other hand, drill bits can only be used for cutting holes in surfaces.
Flutes and Chipload
Providing the endmills power to cut through rough and hard surfaces, flutes are the grooves present on the bits. Each flute on the mills will have one or more cutting edges that help the tool to perform. The more flutes your bit has, the smoother the surface it will deliver.
There are certain end mill types that help in making rougher but faster cuts on the surface. Moreover, the chip load would be the thickness of the provided machined chip. Having a good chip load rate is important as it reduces the heating of the material or tool.
Using a hot cutter might render unsatisfactory results. They might deliver rougher edges, burned wood surfaces, and dull tooling finishes. You must use the single flute bits if you are operating on materials like HDPE plastic. This will help you remove all the chips quickly and avoid melting the material.
Feed Rate & Speed
The speed of the end mill cutting tool being used over the material would be the Feed Rate. At the same time, the rate of rotation of the bits will be termed Speed. The rate of spindle turning endmills determines the speed. Both these aspects will change depending upon the material of use.
The best way to get a sleek finish is to have to be fast in using the tool. This will give you a cleaner finish without sacrificing tool life. The longer you keep the bit in one place, the more heated it will get. And while using endmills, heat is your “Arch Nemesis'' as it can also decrease your tool life.
How to Choose Endmill?
These are the five questions you must ask yourself before buying the endmill:
● Endmill Tool Material
The material you want to work with will help you get the high-performance end mills according to your need. Every material has a different type of mechanical properties that offer exclusive features when in the process with the endmill tool. For example, plastic materials need a distinct endmill machining strategy and different geometric tools than the steels do.
While selecting the endmill, you must know what operation you need to perform. The typical operations of the endmill machining may include:
- Conventional Roughing
- Highly efficient milling
Considering the processes required for a job, a technician may able to complete the operation more professionally. For example, if the job comprises slotting and conventional roughing, selecting the endmill coiling solution for a better carving of the materials would be perfect for an endmill with many flutes.
● Number of Flutes and Material
One of the essential contemplations while looking for the endmill selection is determining the flute's proper count. Both the application and material play a crucial role in the decision of buying the endmill.
When working on the non-ferrous materials, 2-3 flute end mill tools are the most prominent options. Conventionally, the 2-flute options are mostly wanted choice as it enables brilliant chip clearance.
Moreover, the 3-flute option has high-efficiency applications in milling and finishing due to more flute count with more contact points in this material. The ferrous can be machined with 3-14 flutes depend upon the operations that need to be performed.
● Tool Dimensions
After the material's specification and the number of flutes, the operations are going to be performed. The following step is to ensure that the endmill you’ve selected has the correct dimensions for completing the job. You may need to see the following dimensions before buying the Endmill tool:
- The cutter's diameter is the dimension that describes the slot’s width, which is shaped by cutting the tool's edges as it rotates. If you select the endmill cutter diameter in the wrong size, either small or large, it may lead to an incomplete job. For instance, the small end mill cutter offers more clearance of the tight pockets, while large endmill tools offer enhanced rigidity in high-volume jobs.
- The length cut, which is needed for any endmill, should be analyzed by the operation's contract length. When you select the short endmill tool, it will result in a more little setup of the material, less overhang, and chatter. As a rule of thumb, if the machining process required the cutting at a greater depth than the 5 times the toll diameter, it’s best to explore the necked reach substitutes to the longest cut length.
● Coated or Non-coated?
It’s advisable to use the coated end mill tool as when coated tool is used in the correct application; it’ll help to increase the endmill tool performance by offering the following benefits:
- The long tool life.
- The more aggressive running parameters
- Better-quality Chip Evacuation
What is the End Mill Price?
The mold maker may ask the first question when searching for a good quality tool is the end mill price? For this, there is no one answer, as there are different materials and sizes are available. However, the higher-priced tool is eventually proved to have a price much less than one lower-price counterpart. For example, if the tool is priced 3x higher, it performs 5x better.
Here are some of the best Endmills with the best prices available online:
- HHIP high-speed steel end mill set- 6 pieces (35 $)
- HHIP steel single End Center Cut End Mill(7.42 $)
- F&D multiple Flute Endmill(22.76$)
- YG-1 Cobalt Steel square Nose Endmill(34.29$)
- Drill America High-Speed Steel End Mill(5.39$)
There are many choices available in the market for the endmills. You can select from the high-end milling tool, or you can buy the affordable ones; the option is truly yours. However, it's always advisable to invest in a good quality branded endmill.
Many factors are considered before buying the Endmill tool. But, before getting your milling tool, make sure you must know how properly it works. What is an ideal diameter, length, and flutes which you may need in your mold making? What type of endmill is required for the aluminum and the endless steel? Apart from the above guidelines, price and quality is also an important factor. Make sure after reading the above article you will buy the best endmill according to your need.