Why deburring is important and what you should be aware of.
Basic knowledge
Why deburring is important and what you should be aware of
14.09.2019Author / Editor: Markus Lind?rfer / Theresa Knell
Deburring is an important part of the sheet metal process chain. This is because the burrs that frequently occur on sheet metal components during the machining or manufacturing process can be removed in this way.
Related Company
Lamella roller for deburring.
(Source: Markus Lind?rfer)
Why is it important to deburr and what should be kept in mind? The history of sheet metal deburring began in the 1980s. At that time, thin sheets were mainly punched and nibbled; thicker sheets were cut by plasma and oxyfuel. Many processes enable successful deburring. Deburring was mainly carried out in order to avoid the risk of injury, since, for example stamped parts at the exit side of the stamp have razor-sharp edges. On the one hand, the aim was to eliminate the risk of injury in the company's own production, but also during the subsequent use of the product.
With the introduction of the laser, many thought that deburring would soon no longer be necessary, as these machines could cut almost burr-free - at least if the process parameters were set accurately. Eventually, the opposite was the case. While the punched part had a good side and a bad side, it quickly turned out that laser-cut parts, even if they were perfectly cut, have very sharp edges on both sides.
Deburring as a means of choice against sharp edges
In addition, there was the problem of the oxide layer, which accumulates on the narrow side during oxygen cutting (laser beam flame cutting) and poses a problem both during the subsequent coating and during welding.
People realized that the removal of the oxide layer wasn't sufficient to achieve good coating results, because the coating thickness on the sharp edge of the workpiece was thinner than on the surface in both wet painting and powder coating. Consequently, several producers started to develop machines for rounding workpiece edges.
Today, 0.2 to 0.3 mm edge rounding is almost standard. Frequently one is confronted with requirements of 0.5 mm for thin sheets and 2.0 mm for heavy plates. But there are other reasons for deburring and rounding.
ADDITIONAL INFORMATION
DEBURRING MACHINES ARE ALSO USED FOR GRINDING
Since most deburring machines were derived from wood grinders and similar technologies were used, many companies used the machines simultaneously to produce attractive surfaces, for example on the reverse side of one-sided pre-ground, laminated sheets.
But there are other reasons for deburring and rounding: The tools of bending machines suffer from burr formation and are subject to much faster wear if the burr is not removed beforehand. The same applies to the straightening rolls of widely used roll straightening machines. If sheet metal parts are subsequently machined (especially in the thicker sheet metal area), there is also a reason to remove the burr - be it to protect the tools, to enable positioning or clamping.
Sharp edges can also be dangerous for laboratory gloves or for power and compressed air lines that may chafe against these edges. The reasons are manifold and therefore deburring has become an indispensable part of modern sheet metal production.
Let's summarize the most important reasons for deburring once again:
1. Risk of injury:
- For employees during part transport and assembly
- During use and/or repair of the product
2. Coating quality
- Wet painting
- Powdering
- Cathodic dip coating
- Zinc coating
3. Protection of press brake tools
4. Damage & wear of straightening machines
5. Quality of the weld seam (by oxide)
6. Preparation for machining
7. Compliance with standards, e.g. DIN EN 1090
8. Further technical reasons
9. Drawing default
While the term "deburring" basically only refers to the removal of the primary burr (a sharp, right-angled edge would therefore be considered deburred), the following process steps are in fact commonly assigned to deburring.