How metal shearing works and its common defects
Updated: Jul 17, 2021
Metal shearing is an imperative process in the manufacturing industry. It is a primary step in fabricating the sheet metal- trim and removing unwanted materials to make it useful. There are many types of shear used for metal shearing, mainly depending on the type of work and results to be achieved. However, the most common and effective shears are bench shear, guillotine, power shear, and throatless shear.
Bench shear is usually used for cutting rough shapes out of medium-sized pieces of sheet metal, but not suitable for delicate work. While the guillotine shear, also known as precision shear, is most suitable for creating angled cuts and producing perfect straight edges in a fraction of time.
5 common metal shearing defects
Defects in metal shearing are a common occurrence for different reasons. Such defects can disrupt the quality of work and lead to dissatisfaction among customers. That's why it's important to analyze the defects and work on the solution.
It is a common occurrence that just after spearing the metal sheet curls in a spiral or corkscrew. It is caused mainly because of excessive rake angle (angle between the front face of the tool and a line perpendicular to the metal sheet) and sometimes, the metal tends to twist due to its properties. The rake angle must be adjusted by the type and thickness of the material.
Camber is the amount of deflection in the material. This occurs when the metal being sheared moves away from the sheet horizontally. It can be avoided by adjusting the ram speed, adjusting the rake angle, or changing the grain direction of the metal might work.
3. Deformed edges
Deformed edges give the sheared material a rough and unfinished look. This might happen because of the following occurrences.
- Heavily incorrect blade sheer gap
- Dull or damaged blades
- Improper hold-up and hold down pressure
To avoid deformed edges, set the clearance correctly according to the type and thickness of shearing material, make sure the blades are sharp, and check if the material is securely held and is not slipping throughout the process. If still, the problem persists, your machine will require repairing as it might have ram pivot bearing issues.
4. Burred edges
Burred edges are caused either due to an improper gap between shearing blades or dull blades. To avoid burred edges, the operator must have a proper understanding of the material type and thickness, and clearance of the machine to get the best results. Also, ensure the shear blades of the machine are sharp and smooth.
Shearing thin, narrow strips of material require proper attention as the material tends to bow downwards because of the stresses inherent in the material itself. To avoid bowing, reduce the rake angle to the minimum.
Investing in the best quality of shear blades and machines is very crucial to avoid such defects in the longer run.
Industrial Partner, is one of the leading companies which is in service for over ten years. Its core principle is to provide the best services and utmost satisfaction to its customers. With this motive, they produce the long-lasting machinery knives and blades with precision where every step goes through observation and quality check before presenting it to the customers.