The Difference Between Grinding, Polishing, and Deburring
These three machining processes all seem frustratingly similar—so what makes them different from each other?
Grinding, polishing, and deburring—anybody who knows anything about the precision machining process knows that these three processes are a.) crucial, and b.) acts of surface finishing. These three processes are very similar to each other, and for decades have been making people ask the same questions: What’s the difference? And why do we need to do all three processes? Both of these questions are valid, and we have the answers to both below.
The difference between grinding, polishing, and deburring.
1. Grinding
This is the process of removing material and shaping a workpiece into its final form. Grinding can be done on a multitude of materials, such as plastic, ceramic, and many different metals (stainless steel, titanium, high-nickel alloys, etc.). In order to complete this process, grinding wheels of different abrasives are used in various machines made specifically for grinding. It’s important that the correct kind of abrasive is used, as too soft of an abrasive can’t grind a workpiece enough, while too hard of an abrasive will damage a workpiece and result in decreased part quality or scrapped part. Overall, grinding is essential because it improves a part’s surface finish, which not only provides the aesthetic many industries require, but also ensures the removal of pesky surface imperfections.
2. Polishing
Polishing is the process surface finishing, which is also known as the process of improving surface quality. Using softer, smaller abrasives like polishing compounds and wheels, surface imperfections such as scratches and unwanted film/layers are removed to achieve a part’s desired texture (as different industries require different surface finishes). Polishing can be done by hand, machine, or robot, as it doesn’t require quite as much precision as grinding or deburring do. This step can be taken farther with buffing, which gives parts a finish similar to that of a mirror.
3. Deburring
This process is the act of removing burrs from a part’s surface. Burrs are extra bits of metal that form as a part is being cut, and can be extremely harmful both for a part’s functionality and the overall assembly it’s a part of. Deburring can be done by hand or in a machine, though hand deburring proves to be inconsistent and costly. The process of deburring requires extreme precision, as any leftover bit of metal can cause inconsistencies that result in the decrease of a part’s longevity and efficiency. Deburring is required for any part that has been previously machined and can be done on a variety of different materials, such as ceramic, stainless steel, wood, titanium, and more. What makes it an essential process is it ensures parts meet industry standards and helps reduce the possible formation of stress risers.
Surface Profiling
Seeing as all three of these processes fall under surface finishing, it’s important to know how surface finish is measured. Surface profiling is the measurement of a surface’s roughness, which allows manufacturers to know how adequately prepared a part is for further processing, especially when it comes to the part coating and assembly stages. A profilometer is the tool used to measure these surfaces and can be split into two categories: contact and non-contact. Contact profilometers use a stylus to map out the highs and lows of the surface (also known as peaks and valleys) which allow operators to gauge how smooth or rough a workpiece surface truly is. A non-contact profilometer uses image sensors to detect a surface’s texture. While this is the faster of the two profilometers, it’s extremely sensitive to any dirt or oil that may be coating a part’s surface.
Why does manufacturing require all three processes?
Ultimately, grinding, polishing, and deburring are all needed for the same reasons: dimensional accuracy, part efficiency, corrosion resistance, and improved functionality. All of these processes refine parts so they’re safe, functional, and meet industry standards. In other words, it’s the manufacturing equivalent of editing a piece of writing before publishing. A part might work fine enough after it’s just been cut, but without grinding, polishing, and deburring, it probably won’t fit into its assembly correctly, and it certainly won’t reach its ultimate level of efficiency and precision. The time and energy spent on these three process ensure that overall assemblies will require less maintenance, which saves operators and businesses precious time and money.
The Machine that can do it all
One of the most efficient ways of grinding, polishing, and deburring on the market is by using the MAX, an all-encompassing finishing machine sold and manufactured by James Engineering. This deburring and chamfering machine is capable of carrying out all three process concurrently. This means a part can be deburred, ground, and polished in one go. This machine also has a consistent precision unreachable by any hand-done method or other machine. The MAX makes all three processes easy and affordable, which ultimately revolutionizes any operation.
To watch the MAX in action, check out the James Engineering YouTube channel here.
To inquire more about the MAX, call (303) 444-6787 today.
What Is Gear Chamfering?
In simple terms, gear chamfering is the process of cutting a 90-degree edge at a 45-degree angle, but in reality it’s a bit more complicated than that.
Simply put, the process of chamfering is cutting a 90-degree edge at a 45-degree angle as a way to remove stress-rising sharp edges, as well as allow for smoother assembly. That makes chamfering sound easy, when in reality it’s actually very time consuming, no matter the method of approach.
Gear Chamfering can truly be broken down into four separate surface-finishing processes: deburring, chamfering, radiusing, and radius-chamfering.
- Deburring is the process of grinding off burrs, which are bits of excess metal created in the metal cutting process. Burrs are extremely problematic and will cause issues in assembly as well as overall part efficiency. Assuming the deburring has been done properly, all burrs will have been completely removed, leaving nothing but a sharp edge.
- Chamfering, as stated above, is the process of cutting that sharp edge at a 45-degree angle (which is the most common angle, but not the only one they’re limited to). Chamfering can be done with a myriad of tools, such as brushes, sandpaper, grinding wheels, and Scotch-Brite. However, in the process of shaving down this one sharp edge, two more are created on either side of the original, and if the tool being used is worn down, burrs can be created as well.
- Radiusing is the process of completely rounding out edges until it’s completely smooth. While chamfering is smoother than just leaving a part deburred, it still is cut at a noticeable angle that can be seen and felt. Radiusing feels and looks rounded (just like how a ball is round without any hard edge), and can also be carried out via brushes, grinding wheels, and sandpaper. It’s crucial to know what materials these tools are made out of, because the materials will affect the quality of the radius; if a material is too abrasive, it will be impossible to reach a true radius. A true radius is when the edges of a 90-degree angle go tangent to tangent without any surface imperfection.
- Radius-chamfering is when a part receives both radiusing and chamfering. The sharp angle is cut at the usual 45-degree angle, and when those two extra sharp angles are created, they are radiused to create smooth transitions between chamfers.
When it comes to how chamfering is done, there’s a few methods operators can choose from—machine-based, hand-based, or robot-based.
Different types of gear chamfering machines are capable of different sub-categories of chamfering. For example, a CNC machine can decently deburr a part, a lathe can adequately radius-chamfer a part, and a mill can chamfer a part. All of these options are valid, but not a single one of them can chamfer, deburr, and radius a part; separate machines are needed. Not only that, but these kinds of machines require in-depth programming for every single part in order to be exact. The MAX by James Engineering is capable of carrying out all four chamfering processes with heightened precision, as well as little programming.
Doing any of these processes by hand is technically achievable, but it ultimately proves to be more troublesome than it’s worth. Manufacturing is an industry that requires precision, as things will fall apart and fail to work correctly without it, and doing these processes by hand simply does not provide adequate enough precision. Even the best operator can slip or tremble, and man cannot repeatably guarantee a consistent chamfer. Hand chamfering is acceptable in a pinch, especially if only one or a handful of parts require it. But for higher volume operations, not only does hand chamfering not produce consistent results, it also is extremely time and cost inefficient. Scrap rates are the highest with hand chamfering, and the time it takes operators to complete one part is what it would take a CNC to do two or three, or the MAX to do a hundred.
Robots are only slightly better at gear chamfering than when done by hand. While they do have better mobility than most machines, they lack precision. Robots are perfect for operations that require the moving and placing of items, but they just cannot match a machine’s precision. Robots also require a lot of laborious programming, overall making them a poor method of chamfering.
Out of all these methods, the MAX is hands down the most reliable and efficient. As an all-encompassing finishing system, it is capable of deburring, chamfering, radiusing, and radius-chamfering any part or gear, no matter its complexity. It does require some initial programming, but once a part/gear has been loaded in, the MAX will remember it for future use, meaning operators no longer have to manually input adjustments themselves (James Engineering calls these programs “recipes”). The MAX is also capable of repeatable precision down to the fifth decimal. For reference, the average human hair measures to .003 inches. The MAX can repeatably work down to .00001 inches, and even beyond that.
Precision in chamfering is key, because the less precise a chamfer is, it’s more likely that stress risers will appear with continual usage. Stress risers are tiny cracks that form at a part/gear’s weakest point of contact (like the tooth on a gear). If a part is not adequately deburred or chamfered, what will happen is those sharp edges will slowly break off until a part or gear’s structure is ultimately compromised. So that previously mentioned tooth could fall off, for instance. That is extremely dangerous, both for the assembly itself and the people operating it. For example, a helicopter would crash if one of the gears in its motor failed. When it comes to chamfering, the higher the precision, the better. The precision achieved by the MAX means that parts/gears processed through it are extremely unlikely to form stress risers even after years of use.
There’s a misconception about chamfering that it’s done easily. Even with an advanced machine such as the MAX, chamfering is no “easy” feat. If a chamfering operation appears to be “easy”, it’s probably being done sloppily and inefficiently—and precision takes time and effort.
Knowing the correct way to chamfer is a gamechanger with any operation, as well as being able to recognize when a chamfer is done correctly. If it is, parts will fit together with no resistance and work efficiently for the entirety of their lifetime. And when parts work correctly, overall assemblies will perform at their best.
To visibly see how chamfering is done, watch a short video clip here.
To contact James Engineering about the MAX’s chamfering abilities, call at (303) 444-6787
The Dynamic Duo
Why a CNC machine and the MAX System make the perfect pair.
As the demand for parts grows exponentially within the manufacturing industry, so does the need for expert deburring and chamfering. James Engineering manufactures an all-purpose finishing system known as the MAX System that is meant to be paired with CNC machines to produce parts of the highest caliber.
“The MAX is meant to compliment CNC machines,” explains Scott Richards, Vice President of James Engineering. “The MAX allows CNC machines to do what they do best: make parts.”
While CNC machines can deburr parts, they tend to be choppy, aggressive, and slow at it; their primary function is to cut. This means high-volume shops are extremely limited when it comes to both the quality and quantity of parts they’re producing (that is if they rely on CNC machines to deburr as well). The MAX is the solution to this problem—it leaves cutting to the CNC machines and does everything else. “We’re not trying to make a metal cutting machine, or a part manipulator. We’re making a machine that does a delicate job quickly in a way that hand deburring, and CNC machines, can’t,” says Richards. So once the CNC machines can focus solely on cutting, a higher volume of parts can be produced in one day, ultimately heightening a company’s productivity as well as increasing their overall part quality.
Not only does the MAX make overall processing easier, but the machine itself is easily operatable, especially for those who have prior experience with CNC machines. “Within four minutes anybody could learn how to use the machine,” Richards states, “We teach these machines to move into position conversationally, have it catch that point, then move to another position. This is unlike CNC machines, or even robots. If someone new wanted to run a CNC machine, they’d have to understand the language the program is written in; we do not run M- or G-code, we use conversational programming.”
Deburring in a CNC machine can be inaccurate and slow-moving—but that’s because deburring isn’t the main function of a CNC, cutting is. The whole purpose of the MAX is to take the weight of deburring off CNC machines. So while the CNCs focuses on expertly cutting parts, the MAX deburrs, chamfers, brushes, washes, and surfaces all in one go after said parts have gone through the CNC. The MAX will pick up a CNC’s slack, and vice versa, making them the perfect pair. The duo will drastically reduce cycle times while still producing a high volume of expertly processed parts with focus, and without the sacrifice of integrity. For any shops out there running into issues with CNC deburring, or for companies who would simply like to increase their productivity overall, investing in the MAX is the next step you need to make.
Everyone needs a best friend, even machines. Give your CNC its best buddy today and inquire at Sales@James-Engineering.com as to how you can bring your MAX home.