Not just a word you use when you’re cold, metal burrs or burrs are machining imperfections that can form on the edges of almost any of the materials that we offer here at SendCutSend. Burrs form when a part undergoes plastic deformation, which simply means it gets pushed, smashed, or sheared to a point where it doesn’t go back to its original shape.
Although our laser, waterjet and CNC routing services do a great job quickly and affordably getting you the parts you need, there’s always a small burr left over from the initial cutting process. Lucky for you, in most cases our deburring and tumbling service is free and added to your order by default.
Why Deburr Your Metal Pieces?
Burrs are sharp, jagged tears or accumulated slag on the edges of materials that have been cut or sheared. Not only are burrs pose a safety risk to operators, they can also interfere with the fit and finish of metal components, leading to issues like misalignment, poor aesthetics, and decreased functionality.
In precision machining or high-performance applications, burrs act as stress-risers, and ideal places for acids, corrosion, or particulates to catch and build up.
Types of Metal Burrs and Their Causes
There are many types of burrs, depending on the material and the cutting process, several of the most common are described below:
- Breakout burrs are formed when the cutting tool breaks out a piece of material from the workpiece, they are typically large, sharp, and they are often found on the edges of holes or cutouts.
- When the cutting tool tears material away from the workpiece a Tear Burr is formed. Tear burrs are typically smaller than breakout burrs, but they can still be sharp, and they are often found on the edges of machined surfaces.
- The Rollover Burr is formed when the cutting tool rolls the edge of the material over. Rollover burrs are typically small and difficult to see, but they can still be very sharp and cause various assembly problems.
- Poisson burrs are a type of rollover burr that is formed when the cutting tool compresses the material ahead of the cutting edge such as in a blanking or piercing operation.
Although our machines are great at what they do, no cutting method is truly immune to burr formation. At SendCutSend we address this by automatically deburring most orders for free, so you don’t have to think about it. But what if you need very thin parts, or a material that can’t be put through our deburring service? Glad you asked! These are the processes where you’re most likely to see a burr:
- Laser Cutting: the most common type of burr we see is formed when heat from our fiber lasers oxidizes the surface at the air/laser/material interface, leaving a rough slag residue similar to a Breakout Burr. This will primarily show up on the bottom edge, although a little burr may form at the top.
- Waterjet Cutting delivers one of the cleanest, burr-free edges of any cutting method, and we tailor our abrasive size and type, cutting speed and nozzle diameter to get the best results for a given material. A small rollover or tear burr is still possible with waterjet cutting, since the elasticity and other properties of the material ultimately define its response to cuts.
- CNC Routing can cause breakout or tear burrs on the top and bottom edges of the cut. The size and severity of the breakout burrs will depend on the material being cut, the routing bit used, and the cutting parameters, which we optimize for each individual material and thickness. Tear burrs are typically smaller than breakout burrs, but they can still be sharp and hazardous.
- Bending and Forming can cause rollover burrs, particularly on the inside radius edge of the bend. Rollover burrs are typically small and smooth, but will affect the overall width at the bend slightly.
We get it: Burrs are a nuisance and even a safety hazard, so we offer free deburring on all eligible orders. For an additional fee you can also add tumbling to your order. Our deburring process cleans up both the top and bottom edges of your parts, as well as removing any mill scale porosity and most handling scratches from the faces, leaving them smooth and finished. This means your parts arrive ready to go, saving you a lot of extra prep time and maybe even a little cash.
How Are Metal Burrs Removed?
There are literally handbooks full of various methods to deburr a part, but they can be broken down into two general categories: manual methods and automated (or mechanical) processes. We’ll take a closer look at a few of these in a minute, but know that while inexpensive, manual deburring takes more time and delivers less consistent results, while automated mechanical deburring methods give excellent, quick and consistent results, but typically cost tens of thousands of dollars to set up.
SendCutSend offers the best of both worlds: our deburring service is rolled into the price of eligible parts so you automatically get great consistency without the time spent. Also note that not all materials deburr equally well with each tool. We’ve got that covered too; our machine settings are dialed in for the specific material and thickness so all you see are great results.
Types of Deburring
The most common method, manual deburring, involves using hand tools such as files, scrapers, and brushes, to remove burrs from the edges of the metal or plastic part. Manual deburring is a labor-intensive process, and it can be difficult to achieve consistent results without jig or fixturing the workpiece, which adds time.
- Deburring Tools: Deburring knives, scrapers, and rotary deburring tools. They are effective for small-scale deburring tasks.
- Hand Filing: For manual removal of burrs on metal or plastic, hand files and emery cloth can be used. This method allows for precise control and is suitable for smaller pieces and tight corners.
- Sandpaper or Abrasive Pads: Sandpaper, abrasive pads, or sanding blocks can be used to smooth out burrs on various materials. They are often used for finishing and polishing in addition to deburring.
- Chamfering: Chamfering is the process of beveling off the sharp edges of a material. It not only removes burrs but also provides a smoother, safer edge.
Used in a production environment for high-quantity parts, automated deburring is typically tailored to the specific needs of the end product.
- Electrochemical Deburring works by passing an electric current through a solution of electrolyte and water. The part to be deburred is connected to the positive terminal of the power supply, and a cathode is connected to the negative terminal. It’s effective for precision components but requires specialized equipment.
- Thermal Deburring, also known as explosion deburring, involves placing the workpiece in a chamber filled with an oxygen-rich atmosphere and igniting it to burn away the burrs.
- Cryogenic Deburring: on the opposite end of the temperature spectrum, this method uses extremely low temperatures to freeze and then fracture the burrs. It’s effective for both simple and complex parts.
- Vibratory Deburring: Parts are placed in a vibrating bowl or tub with abrasive media. The vibratory action removes deburrs and polishes the parts.
- Tumbling is similar to vibratory deburring, and involves placing parts and abrasive media in a rotating drum or barrel. The friction between parts and media removes burrs and leaves a smooth and consistent finish on all part surfaces. We use ceramic media to tumble smaller parts because it’s durable, safe, quick, and most importantly, effective across a wide range of materials including steels, brass, copper and aluminum.
- Linear deburring uses a series of rotating brushes to remove burrs from metal parts. It is a quick and effective method that can be used to remove burrs from a wide range of materials and flat part geometries.
Linear deburring machines typically have a conveyor belt that pulls the parts through a series of brushes arranged in stations, with each station performing a specific task. The brushes are made of a variety of materials, including nylon, abrasive, and wire depending on the material of the part and the severity of the burrs. At SendCutSend most of your parts will see the linear deburring machine after being laser or waterjet cut because it’s quick and effective, with great results.
FAQs About Metal Burrs:
- What is a burr?
A burr is a small, raised edge or ridge that can form on metal and plastic parts during machining or other cutting processes. Burrs can be caused by a variety of factors, including material, the type of cutting tool, and the machining parameters.
- What tool is used to remove burrs?
There is a huge variety of tools that are used in the burr removal world, including manual tools such as files, scrapers, and brushes, and automated deburring processes such as linear deburring and tumbling (hey, we offer both of those!). The best process use will depend on the specific application.
- Why is it important to remove burrs?
Burrs can be a nuisance and even a safety hazard. They can interfere with the proper fit of parts, reduce strength and durability, and increase the risk of corrosion. This is what you should expect from our deburred edges.
- What are the different types of metal burrs?
Most common types of burrs are breakout burrs, tear burrs, and rollover burrs. Breakout burrs are formed when the cutting tool breaks out a piece of the material, like when our laser pierces through the metal workpiece. Tear burrs are formed when the cutting tool tears material away from the workpiece, think drill-bit. Rollover burrs are formed when the tooling rolls the edge of the material over, which can occur during the bending process.
- How can I prevent metal burrs from forming?
There are a number of things you can do to prevent metal burrs from forming, including using sharp cutting tools, the correct cutting speed and feed rate, and a backup material. You should also design the part carefully to avoid sharp corners and edges. Here at SendCutSend, we take care of all but the design!
- Where can I get my metal parts deburred?
So glad you asked: If you prefer to micro-manage, you can deburr them yourself. If you like to save time and money, leave that deburring checkbox ticked in our App when you order.
The Perfect Finish For Your Metal Pieces with SendCutSend
SendCutSend offers a convenient way to deburr nearly all your metal and plastic parts for free, and best of all, it’s automatically added to individual parts when applicable.
Although we can’t guarantee a part with a perfectly smooth cosmetic finish, we can promise that when you upload and order a part with deburring through our App it will have a fantastic finish that’s smooth and ready for use.