Blade chipping on a CNC shearing machine can result from excessive cutting loads, incorrect blade clearance, unsuitable workpiece materials, or poor blade quality. Identifying the cause is necessary to prevent further damage and maintain consistent cutting performance.
Material Hardness Exceeds the Blade's Capacity
When the material being cut is harder or stronger than the machine and blade are designed to handle, the cutting force may exceed the blade's capacity. This can cause localized damage, chipping, or cracking along the cutting edge.
How to prevent it: Select blades suitable for the material grade, hardness, and thickness. Check the machine's rated cutting capacity before processing unfamiliar materials. Do not use the same blade specification for every material without confirming its suitability.
Incorrect Blade Clearance
The clearance between the upper and lower blades directly affects cutting force, edge quality, and blade loading.
If the clearance is too small, the blades may experience excessive friction and loading during cutting. If it is too large, the material may deform excessively, resulting in poor cut quality and uneven loading. Either condition can contribute to premature blade damage.
How to prevent it: Set the blade clearance according to the material thickness, material properties, and machine manufacturer's specifications. Check the clearance along the cutting length and confirm that the blades are correctly aligned and securely mounted before resuming production.
Cutting Round Bars or Other Unsuitable Materials
Round bars and other non-flat workpieces can impose concentrated or uneven loads on blades designed for flat sheet metal. This increases the risk of chipping or cracking, particularly when the material is not properly supported.
How to prevent it: Use a machine specifically designed for the intended workpiece shape. A conventional sheet metal shearing machine should not be used to cut round bars unless the manufacturer approves the application and specifies suitable profiled blades and supporting arrangements. Select an appropriate cutting process when the workpiece falls outside the machine's rated capabilities.
Poor Blade Quality or Incorrect Heat Treatment
Blade material, heat treatment, hardness, and toughness all affect service life. A blade with insufficient hardness may wear prematurely, while a blade that is too brittle may chip or crack under impact or excessive loading. Manufacturing defects or incorrect heat treatment can also reduce reliability.
How to prevent it: Purchase blades from reliable suppliers and confirm that the material grade and heat treatment are suitable for the intended cutting conditions. Inspect the cutting edges regularly for chips, cracks, and wear. Regrind or replace damaged blades according to the manufacturer's requirements.
Preventing Blade Chipping During Operation
Blade chipping can often be avoided through correct blade selection, proper clearance adjustment, and routine inspection. Before cutting, confirm that the material is within the machine's rated capacity and that the upper and lower blades are aligned correctly.
If chipping occurs, stop the machine and inspect the blades, mounting surfaces, clearance, and workpiece material. Do not continue cutting with a damaged blade, as the damage can worsen and compromise cut quality.
Custom Precision Machining for Industrial Applications
Hansheng Automation provides custom precision machining based on customer drawings for a range of industrial applications. Our work includes precision components for yacht equipment and RC racing cars, as well as nonstandard parts for tobacco packaging machinery and filling machinery. Each component is manufactured according to the supplied drawings and the specific dimensional and structural requirements.
