After the deburring process, the burrs on the sheet metal part have been removed, but the edges remain sharp (Figure 1).
If the customer’s drawing specifies a radius requirement for the sheet metal edge, the machining company must provide the necessary edge rounding.
Reasons for Edge Rounding
Improved coating adhesion after edge rounding
During spray processing, whether using liquid or powder paint, paint tends to run off the edges of the sheet metal. The paint may slide off sharp edges or burrs during curing, preventing a complete sealing layer.
The unprotected edge of the sheet metal is then exposed to air and external elements.
Thus, sheet metal parts that require painting should not have sharp edges, especially if the material is prone to corrosion.
Necessity of Edge Rounding for Galvanized Parts
In the zinc plating process, there’s no issue of paint running off the edges. Even at sharp corners and edges, the coating will automatically attain a thickness at least equal to the surface coating.
However, there’s still a need for edge rounding in galvanized parts. The reason being that the zinc layer near the edge is more sensitive to mechanical loads or impacts than smoother surfaces.
Therefore, individual galvanized components, even if they pass inspection after galvanizing or arrive undamaged at the construction site, might soon exhibit edge defects.
Microscopic images reveal that, based on the steel composition, the zinc layer structure on sharp edges shows clear signs of being affected. Sheet metal parts of the same material, even with minimal edge rounding, display a more uniform coating structure.
For instance, the DN EN1090 standard requires that the edges of steel structural sheet metal parts be rounded to a radius of at least 2m, ensuring the anti-corrosion effectiveness of the sheet metal.
Edge Rounding Prevents Equipment Downtime
Some sheet metal processing companies often overlook rounding the edges of internal components, leading to frequent equipment failures.
This is because, during equipment operation, pneumatic or hydraulic hoses, as well as cables, move back and forth. If these hoses or cables move along sharp metal edges during continuous operation, they will inevitably get damaged.
Rounding the edges of sheet metal is the most direct and effective way to eliminate this risk.
Edge Rounding Prevents Workplace Injuries
Sharp edges on sheet metal are as dangerous as a razor blade and can easily cause personal injury. Every company wants to avoid such injuries, making edge rounding an essential process.
Similarly, when handling parts or tasks that require protective gloves, these gloves shouldn’t be cut by sharp sheet metal edges. Therefore, edge rounding of the sheet metal is indispensable.
Edge Rounding for Safety at Work
Beyond customer requirements, the employees of the machining company also benefit from the edge rounding process.
Just like users, they might get cut by sharp sheet metal edges. Protective gloves offer some protection, but they wear out over time.
Hence, edge trimming and rounding ensure better safety during operations.
Wrap It Up
In summary, edge rounding is one of the many tasks undertaken by the deburring machine.
Sheet metal parts that have only undergone deburring still have sharp edges, which can pose risks in subsequent processing.
You can choose to equip the deburring machine with a special edge rounding tool as a secondary process after deburring.
This not only rounds the edges but also removes secondary burrs that may have formed after the initial deburring process.