1. Core process of sharpening (three-stage progressive method)
Rough sharpening of micro-serrations (80 mesh diamond)
Operation points:
The grinding wheel is tilted at about 45°, the handle faces forward, and the grinding wheel is evenly pushed to contact the grinding wheel surface.
Continue to grind until the edge is fully curled (the curling evenly covers both sides of the edge line as a sign of compliance).
Function: Quickly establish the basic edge shape and improve cutting efficiency.
Fine deburring (3000 mesh polycrystalline diamond)
Operation points:
Maintain the same tilt angle as rough sharpening, and gently unidirectionally Push (no back and forth friction).
Burr removal standard: The blade feels smooth, no visible rough spots.
Ultimate sharpening (20000 mesh sponge diamond)
Operation points
Lightly grind in the direction perpendicular to the blade grain, and only push in one direction for each process (avoid pulling back and causing chipping).
Final effect: The blade is mirror-smooth, without microscopic sawtooth residue.
Industry verification method
Paper towel pressure test method to test sharpness – light pressure on the blade can instantly cut off the paper towel fiber for qualified (refer to Zheng Haibin test method).
Second, key operation taboos
Angle out of control
The blade angle must be strictly matched with the grinding wheel design (commonly used 15°-30°). Too large an angle will lead to blunting of the blade, and too small an angle will easily break.
The hardness of the diamond grinding wheel is ≥8000HV, and the angle deviation >5° may damage the substrate.
Reverse grinding
Pull-back operation is strictly prohibited! Reverse force on carbide grinding wheels will cause micro-cracks (refer to the lesson of sharpening tungsten carbide engraving knives) .
Pressure overload
Pressure in the fine grinding stage (≥3000 mesh) needs to be less than 2kg/cm², overpressure will cause abrasive particles to fall off
III. Performance calibration after sharpening
Dynamic balance correction
Meet G6.3 standard (residual imbalance ≤0.5gmm/kg), prevent high-speed operation vibration.
Detection method: Test with a special dynamic balancer, mark the weighted area and then drill to reduce weight.
Blade strength test
Push-pull force ≥180N (A-level standard), repair is required if it is lower than this value 7.
Simple verification: Use a copper rod to gently scrape the blade edge, and no abrasive particles fall off for qualified.
IV. Maintenance and fault prevention
1. Grinding efficiency drops sharply – Micro-serration is blunted or blocked – 80 mesh re-curling → 3000 mesh deburring.
2. Scratches on the workpiece surface – Residual burrs on the cutting edge – re-polish with 20000 mesh.
3. Abnormal noise/vibration of the grinding wheel – dynamic balance failure or dry bearing – add lubricant + re-calibrate dynamic balance.
Life warning:
The continuous working temperature of the resin bond grinding wheel must be less than 180℃, and it will decompose and splash if it is overheated; metal bond should avoid sudden changes in temperature.
