· KAIPU Engineering · glossary · 2 min read
Chipping — Industry Glossary Entry
Definition of chipping in industrial cutting: small fragments breaking off the cutting edge, the four root causes, and how edge hone, hardness and impact load determine chipping resistance.
Chipping is the loss of small fragments of material from the cutting edge of an industrial blade. Chipping is distinct from wear (which is a gradual loss of edge material) and from gross fracture (which is a catastrophic break of the whole knife). Chipping is the failure mode that turns a “worn-out” knife into a “scrap” knife.
Visual tells: Visible fragments missing from the edge, typically 0.1–2 mm in size. May be accompanied by a wire-edge or rolled edge. Burr grows on the chipped side. Cut surface shows scratches or tears downstream of the chip.
The four root causes:
- Edge hone too sharp. A 0–2 µm hone on a substrate that demands 5–15 µm will fail by micro-chipping within hours.
- Hardness too high. HRC 64 on a 1.5 mm section, on a substrate that allows HRC 60, will chip. Hardness is a wear-vs-toughness trade; a 4-point drop buys 30–50 % more chip resistance.
- Impact load. Granulator rotors, swing-beam shears with misaligned stock, crusher blades. A D2 or HSS knife on a high-impact line should be HRC 58–60, not HRC 62–64.
- Heat-treat defect. Decarburisation leaves a soft surface. The hard substrate beneath cracks the soft skin on impact. A 5-point file test catches it.
By substrate, the chipping tendency:
- Paper, tissue: low (low impact, low hardness demand)
- Film, foil: low–medium (thin section, sharp edge)
- Plastic (neat): low
- Plastic (glass-filled): medium (abrasive, some impact)
- Stainless plate: high (work-hardening, demands hard knife)
- Corrugated: medium (abrasive, occasional metal)
- Recycled polymer: high (contamination, impact)
- Food / meat-bone: high (impact, contamination)
Fixes, in order of cost:
- Add hone (0.05–0.10 mm chamfer or 10–15 µm micro-hone). Cheapest fix.
- Drop hardness 2–4 HRC points. Drops wear life 10–20 % but doubles chip resistance.
- Move to a tougher steel grade (D2 → M2 HSS, M2 → M42, YG6X → YG8).
- Audit heat-treat (5-point file test, mill certificate, decarb-free guarantee).
- Fix the upstream problem (substrate contamination, line alignment, knife clamp).
See also: Troubleshooting: why is my blade wearing out too fast?, The KAIPU 5-Factor Blade Selection Framework, Hone (micro-hone), Clearance angle.