Deburring – What is a burr? Occasionally, you will notice small pieces of protruding metal remaining after you’ve finished modifying an item. These pieces are called burrs and they can ruin an otherwise perfect process.
In the machining business, we see far too many people making mistakes when deciding whether
their metal needs graining, finishing, or deburring. It is often assumed that you could simply run
the metal through a sanding or graining machine in order to remove the burrs. This sounds good on
paper but in reality, there are many factors that lead to burrs in the metal and there are just as many
variations in the deburring process. The first thing to determine is what type of burr you have.
Typically, burrs fall into two categories: thermal and mechanical. Thermal burrs are the result of
oxyfuel or laser cutting while mechanical burrs result from shearing or from punching holes when
the punch and die are not fitting perfectly.
Although the graining process (which involves using a sanding belt on the metal surface) is
commonly referred to as deburring, it does not actually remove any burrs. It can affect the shape
and/or position of the burr by making it sharper but it will not completely remove it. To remove the
burr, a deburring and graining machine is needed. These machines will have two or more heads.
One head will have a sanding belt to knock the burr down and the other head with have a brush
which can eliminate the burr as well as give a radius to the edge. 
Above is an FP-4075W Finishing-Deburring Machine (wet)
Also to be considered is whether you want to use a wet or dry machine. A wet machine will
keep the belt in peak condition longer than a dry machine. A wet machine will also offer a better
finish and help remove grit from the parts. The downside is the amount of maintenance required.
Dry machines, though requiring less maintenance can be dangerous if not used properly. For
example, processing aluminum and stainless steel with a dry machine can cause an explosion if the
dust from the two metals is allowed to mix. For this reason, it is vital to use some sort of wet dust
collection system with a dry machine.
