What Is Deburring?
If your shop regularly machines parts, you've probably had to deal with unwelcome burrs on your workpieces. These imperfections are unsightly, and more importantly, they reduce the functionality and safety of each affected part. You need a reliable way to remove burrs and provide smooth, quality components. Deburring machines offer an ideal solution. The guide below will describe what causes a burr, explain why deburring is so critical and discuss how to remove burrs from metal.
DefinitionDeburring is the process of removing the small imperfections known as burrs from machined metal products. Machining processes shape a piece of metal in different ways. Stamping, for instance, presses the workpiece in a die set, while milling uses a rotating tool to shave metal off a workpiece. Processes like these don't always work perfectly, though — they may leave small ridges or protrusions of metal known as burrs. Burrs compromise the quality of the finished part if they are not removed. After machining or welding, deburring removes these imperfections to provide a smooth, reliable metal part.
What Causes a Burr?Burring is an extremely common occurrence during the machining process. Burrs may appear during several different stages of machining:
- Plasma cutting
- Waterjet cutting
- Laser cutting.
- Rollover burrs: Rollover burrs are the most common types of burrs. They look like tiny bits of curled metal projecting up from the workpiece.
- Poisson burrs: Poisson burrs occur when too much metal collects at the end of the workpiece and extends sideways.
- Breakout burrs: Breakout burrs have a characteristic upswelling shape that makes them look like they are breaking out of the workpiece.
How Do You Remove Burrs From Metal?Fortunately, deburring is relatively easy with the right tools and techniques. Deburring may take a few different forms depending on the metal and application in question:
- Manual deburring: Manual deburring is the most common and economical deburring method. In manual deburring, experienced technicians scrape or buff the burrs out of the metal pieces by hand using simple tools. Though this process is easy, it is time-consuming and can dramatically reduce productivity.
- Mechanical deburring: Mechanical deburring uses a deburring machine to grind the burr off. This method is costlier but much more efficient than manual deburring, so it is a popular option in machining operations.
- Thermal deburring: Thermal deburring uses combustive gases to generate thermal energy and essentially scald the burrs out of the metal. This process is often ideal for getting out the most hard-to-reach burrs — those in cracks or crevices, for instance — or addressing burrs on multiple surfaces simultaneously.
- Electrochemical deburring: Electrochemical deburring uses a solution of salt or glycol to conduct energy through the burrs. The electrochemical energy blasts away the burrs while leaving the surrounding metal intact. This process is most useful for working with extremely challenging metals, reaching difficult areas or ensuring high precision in burr removal.
How Does a Deburring Machine Work?What does a deburring machine do? A typical deburring machine contains one or more tools for smoothing burrs out of the machined metal. The orientation of the tools allows for consistent, quality deburring. Many deburring machines use brush, disc or belt heads for grinding burrs out of workpieces. Some machines use a single head, whereas other more advanced machines use several:
- Brush heads: Rotating brush heads work effectively on small, delicate parts because they can remove unwanted burrs without damaging the metal or its surface coatings. They are also highly effective at edge rounding and can generally rotate through 360 degrees to reach inaccessible areas on the workpiece.
- Disc heads: Disc heads are also well suited to small, delicate parts. Their rotating pads create a distinctive pattern that helps to keep the workpiece from fracturing under stress.
- Belt heads: Belts run on continuously turning drums. They have excellent reach and can effectively remove burrs from a workpiece's edges and sides. One downside, however, is that though they are well suited to removing vertical burrs, they can sometimes shift material to the sides of a workpiece, creating new lateral burrs.
- Aluminum oxide
- Cubic boron nitride (CBN)
- Silicon carbide.
Why Is Deburring Necessary?A machined piece that contains burrs is flawed. Burrs compromise the functionality, lifespan and safety of a machined part. They can cause numerous part quality issues like these:
- Cracks and material failures
- Increased localized stress
- Decreased fracture resistance
- Failure after fewer stress cycles
- Poor fastener seating
- Fastener damage
- Increased susceptibility to corrosion
- Increased risk of static discharge
- Undesirable friction and heat
- Increased surface-to-surface wear
- Lubrication issues
- Overall diminished safety.
- Edge breaking
- Descaling before painting and further processing.