Techniques to Remove Sharp Edges and Burrs from Metal

May 26, 2021

Techniques to Remove Sharp Edges and Burrs from Metal

Metal parts cannot be used right after the cutting process. Many metal pieces, produced by stamping or machining, require further processing before being safely assembled or used. The method of removing the sharp edges and burrs is called Deburring, or burr removal. It is a necessary step within the metal finishing process.

There are many ways to get rid of sharp edges and burrs quickly and affordably from metal parts, including vibratory finishing and barrel tumbling. 

Practically every metal cutting process leaves a burr. It's a security hazard, but it also can affect how your parts go together and perform in commission.

What is Burr?

A burr isn't always a pointy edge; it's more sort of a sharp little tooth sticking up from the cut edge. Burrs are the results of plastic deformation, which is what happens when metal is sheared. Some metals deform quite others, then form larger burrs. Generally speaking, it's softer metals like aluminum that make the most critical problems.

Consider a punching operation as an example. The punch comes down and pushes the metal into a hole, the die. When the punch hits the metal, the metal shears through round the edge, but before cracking, (which is what happens,) it bends into the opening. As there has got to be clearance between punch and die, there's room for a touch burr to make.

Any cutting operation that deforms metal leaves a burr. Punching, cutting, and slitting are all guilty of it. Processes that don't involve deformation generally don't leave burrs. For instance, electrochemical machining and, to an extent, laser cutting is largely burr-free. 

Why is Burr-Removal Important?

There is a minimum of three reasons you don't want burrs on the sides of your metal parts:

  • Safety. Even the littlest burrs can leave deep lacerations on the hands of the unwary. That's true within the fabrication shop but also wherever the parts or fabrication find yourself. Nobody wants people to be injured by burrs.
  • Fit. Parts might all be move length, but if they need burrs on their edges, likely, they won't go together correctly.
  • Function. Perhaps a fabrication did go together correctly, but if there are burrs thereon, it will not function properly or could fail prematurely. Eventually, the burrs will break off and will get drawn into a pump or fan. Alternatively, a hose or cable might rub against burrs on a foothold. Any vibration will have those burrs acting like tiny saw teeth, quickly cutting through the sheathing.

Techniques to Remove Burrs

The deburring and sharp edge removal involves quite 80 different processes currently in metal manufacturing.

Some of these methods require more manual labor, while others are automated. There's also a systematic difference. you'll apply thermal or mechanical methods to get an excellent result.

Here are some standard deburring methods to help you identify the most uncomplicated deburring process for your metal parts.

Manual Deburring

It is the oldest and most elementary method to eliminate burr. It requires a skillful artisan to ensure the simplest results. Therefore, it's a way that takes tons of your time and energy.

It is a time-consuming technique and is mostly utilized in small shops with a coffee production rate. Cleaning large batches isn't cost-effective, but having the specified skills within the workshop may are available handy.

Standard tools wont to apply this method include deburring knives, files, sandpapers, and other polishing tools.

Punch Deburring

This method utilizes a punching machine for burr removal. It requires differing types of dies for the punch mold work, including rough blanking, dies, fine blanking dies, and sizing dies.

Hole Deburring

This method is employed when deburring is required on the inner part of a hole. There is a spread of tools to use this method available within the current market, but they typically have an equivalent configuration.

A cutter is spring-loaded and mounted on a spindle. This tool is positioned to undergo the opening smoothly and comes out by touching the surface with the sting that cuts the burr without causing any scratches or damages. A number of the cutting tools accompany a tapered end that permits to make a chamfer at the front of the opening when entering.

Brushing

Considering the name of the tactic, it's easy to deduce that, in this method, the burr is removed by "cleaning" the surface with a particular sort of brush.

The method works in a similar way thanks to manually deburring with sandpaper and similar tools. The deburring brushes are usually made from abrasive materials with a selected grit number.

The main difference is that most of those brushes are designed to mount them on machine tools, making the method more efficient and giving the likelihood of automating this manufacturing step.

Electrochemical Deburring

This method is usually used on small metal parts with a burr in areas that can't be reached by other deburring processes. It's the reverse operation to the plating. Rather than adding material, electrochemical deburring eliminates it.

This process uses a tool with a shape almost like the sting being deburred. The tool, during this case, an electrode, works alongside an electrical current and an answer of common salt or soda niter as an electrolyte.

Tumbling

Another way to supply an excellent finish for your metal parts is during a vibrating or centrifugal container. The barrel contains a mix of abrasives and liquids. Those start moving and rubbing against the metal parts due to the vibratory movement.

It results in eliminating burrs without scratching the surface besides removing burrs, deburring by tumbling leaves an excellent overall surface finish to the parts.

Grinding and Rolling

If you're trying to find a high-quality finish without an excessive amount of hassle, mechanical deburring by grinding or rolling could also be for you. While somewhat almost like manual deburring, it's much faster and thus cost-efficient

Thermal Deburring

Also called Thermal Energy Method (TEM), it's mainly used to treat many pieces and everyone on their surfaces at an equivalent time. The burr is eliminated by burning the fabric during a controlled combustion chamber. A mix of oxygen and gas is usually used because of the energy source.

The most crucial step is determining the proper proportion of oxygen and fuel that has to be used to generate enough heat to get rid of the burr without hurting the piece.

Conclusion

The most cost-effective way of working is minimizing the number of processes. Therefore, we recommend turning to a manufacturer capable of providing clean parts without burr whenever possible.

But with specific materials and thicknesses, it's just impossible. Of course, the burr is merely on one side of the fabric.




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