In metal fabrication, a burr is a bit of residual metal left over from the casting, stamping, lathing or laser cutting process. When forming sheet metal into precision parts for autos, aircraft, or machinery, tools that mold, cut, bore holes, or form metal into curves may leave rough edges or excess metal pieces along seams or within holes. These tiny imperfections can render parts unusable. Sharp edges can cause injury, and burrs might catch on moving parts and create accidents or malfunctions. Burrs also interfere with further finishing techniques like painting or coatings. Metalworking shops perform a finishing process called deburring on these parts. Here are five different techniques to remove metal burrs.
Sanding or filing powered by good old-fashioned elbow grease, or in the case of filing, by electric or pneumatic power, was the original method of deburring metal. Manual deburring is more appropriate for less complex, larger, or one-off cast, milled, or stamped parts. It is labor intensive and costly.
This process is essentially an automated form of manual deburring, using machines with specially designed brushes attached. The brushes rotate while passing across the surface of the metal repeatedly to clean off burrs.
Also known as cryogenic deburring, freezing a part causes the burrs to become brittle, and then they can be removed with an abrasive spray. Cryogenic deburring processes use liquid nitrogen to freeze parts quickly. The parts then go through a machine with abrasive media that creates friction to remove the frozen, brittle burrs.
Vibratory or Tumbling Deburring Machines
Vibratory or tumbling deburring machines, like a Mr. Deburr finishing machine, do the job efficiently, processing parts continuously or in batches. A rectangular bin, barrel, or bowl rotates or shakes the parts together with abrasive media and sometimes specially formulated liquid or water. The vibratory or tumbling motion, combined with the friction the media creates, files the burrs off parts. This kind of deburring can be effective for many kinds of parts, including those with holes or complex shapes. When the process finishes, the parts separate from the media and move on to the next phase of manufacture. This next phase may include additional polishing, application of a coating, or painting.
These are just some of the different techniques to remove metal burrs. Others include ultrasonic, electrochemical, thermal, and explosive methods. Most shops do well with vibratory or tumbling deburring machines. Contact AccuBrass for options for your shop.
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