1.Applicable to most metal materials. What is the solution when burrs are obvious?
Mechanical grinding method
Manual grinding
Tools: sandpaper (coarse sand → fine sand), emery cloth, files (flat files, round files), grinding stones, etc.
Applicable scenarios: small batch workpieces, special-shaped parts or local burrs (such as sharp corner burrs on the edge of punching).
Advantages: flexible and controllable, can deal with fine burrs in a targeted manner; Disadvantages: low efficiency, quality depends on the skills of the operator, and uneven grinding is prone to occur.
Mechanical automatic grinding
Sanding belt machine: suitable for continuous grinding of flat workpieces, and the effect is controlled by adjusting the sanding belt particle size (coarse sand to remove large burrs, fine sand to polish).
Grinding wheel/grinder: use high-speed rotating grinding wheel or grinding head to grind burrs, suitable for larger burrs or thick plates (such as steel plates after punching).
Wire wheel: remove burrs through high-speed friction of metal wire, and clean the surface oxide layer at the same time, suitable for softer materials such as galvanized plates and aluminum plates (to avoid scratching the substrate).
2.Which method is suitable for mass production?
Deburring machine (chamfering machine)
For the edge burrs after punching, the edge of the hole is chamfered by a tool or grinding wheel (removing burrs and forming rounded corners at the same time), which is suitable for batch processing of plates and pipes (such as frame burrs after color-coated plates are punched).
Type: hob type (suitable for continuous punching of flat plates), turntable type (suitable for holes of multiple specifications), adjustable chamfer size (such as 0.1~1mm).
Vibration grinding / centrifugal grinding
Principle: Put the workpiece and the grinding medium (such as abrasive particles, ceramic beads) into a vibration trough or centrifugal barrel, and make the workpiece and the medium rub against each other through high-frequency vibration or rotation to remove burrs and polish.
Applicable scenarios: Batch deburring of small-sized workpieces (such as screws and gaskets), especially suitable for complex surfaces of special-shaped parts (such as internal and external burrs of porous stamping parts).
Advantages: High degree of automation, can process multiple workpieces at the same time, taking into account deburring and surface finishing; Disadvantages: Not applicable to large workpieces, the medium needs to be replaced regularly.
Sandblasting / Shot Peening
Use high-pressure airflow to spray abrasives (such as quartz sand, steel shot, ceramic sand) onto the surface of the workpiece, remove burrs through impact force, and clean the surface oxide scale or coating (such as color-coated plates after punching, deburring and processing edge coating defects).
Applicable scenarios: burrs of thick plates and high-strength materials (such as steel plates, cast iron parts), or workpieces that need to be cleaned at the same time.
Note: The abrasive particle size must match the burr size (coarse abrasives remove large burrs, fine abrasives for fine processing) to avoid excessive spraying and damage to the substrate.
3.How to prevent burrs?
Adjust the punching process parameters
Control the punching speed and pressure to avoid excessive plastic deformation of the material due to excessive impact force, resulting in burrs.
For thicker materials (e.g., steel plates > 3mm), use step-by-step punching (pre-punching + fine punching) to reduce the burrs of a single punching.
Choose the appropriate material state
Hard materials (e.g., cold-rolled hard steel plates) have smaller burrs when punching than soft materials (e.g., annealed steel plates) (soft materials are prone to plastic tensile burrs).
4.How to choose in different situations?
Small batch, simple workpieces: manual grinding or belt sander processing is preferred; Large batch, standardized workpieces: vibration grinding, deburring machine; Precision parts, small/complex burrs: chemical deburring or electrolytic treatment; Thick plates, large burrs: mechanical grinding (grinding wheel, wire wheel) or sandblasting.
5.How to optimize punching dies?
Ensure that the gap between the punch and the die is reasonable (e.g. the gap for low carbon steel is about 5% to 10% of the material thickness). If the gap is too large, it is easy to cause tearing burrs. If the gap is too small, the die will wear quickly and the burrs will easily stick to the cutting edge.
Grind the cutting edge of the die regularly to keep it sharp (a dull cutting edge will cause the material to be squeezed rather than sheared, resulting in coarse burrs).