Industry Solutions
From printed reels to recycled pellets, our knives are specified to the cutting geometry, material grade and tolerance your process demands. Twenty-five years of focused manufacturing, ISO 9001 certified since 2001.
Why lines stop
Lines running abrasive composites, glass-filled polymers or recycled feedstock can lose 0.2–0.4 mm of edge per shift. The root cause is almost always a mismatch between substrate and cutting geometry, not the hardness number alone.
Tissue and paper converters measure reject rate in basis-weight points. A 50 µm burr change can lift reject from 0.3 % to over 2 % — and most operators blame the steel when the real fault is the grind angle.
Food processors and pharma OEMs cannot ship a part that does not trace back to certified material and documented heat treatment. A supplier without lot traceability is a single audit away from a line shutdown.
Industries Served
Each industry carries its own cutting mechanics — web tension, abrasive wear, hygiene grade, throughput. We tune the blade geometry and steel grade to match. KAIPU has supplied converters, recyclers and OEMs across four continents since 1998.
Slitting, sheeting and rewinding blades for paper, film, foil and laminate. Tight burr control protects printed surfaces and clean edges. Materials specified per ASTM A681 (D2) and JIS SKD11.
Long-life bed knives and top blades for tissue converting lines. Optimised cutting angles reduce dust and extend service intervals. Compatible with 600–2,400 m/min tissue lines.
Stainless and tool-steel blades for slicing, dicing and portioning. Designed for washdown environments and food-contact compliance. Material traceability documented per ISO 9001:2015 §8.5.
Granulator and shredder rotor / stator knives engineered to cut through contamination, glass fibre and reinforced polymers. D2 and M2 HSS options, with optional TiN or CrN coating to extend interval by 2–4×.
Trim and score blades for pouch-making, label stock and adhesive tape lines. Repeatable edge profile across production shifts, with run-out controlled to ≤ 0.01 mm on Ø 250 mm blanks.
Shear blades for guillotine and swing-beam cutting of mild steel, stainless and aluminium plate up to 12mm. HRC 58–62 working hardness, ground and polished to ≤ Ra 0.4 µm.
Material selection
A quick reference for buyers specifying a new blade or auditing a failing one. Hardness range and best-fit application; tolerances and dimensions are confirmed per drawing.
| Material | Equivalent standards | Hardness (HRC) | Best for | Not suitable for |
|---|---|---|---|---|
| D2 (1.2379) | ASTM A681, DIN 1.2379, JIS SKD11 | 58–62 | Paper, film, foil, laminate — general slitting and sheeting | High-impact shredding, thin blades under 1.5 mm |
| M2 HSS (1.3343) | ASTM A600, DIN 1.3343, JIS SKH51 | 60–65 | High-speed slitting, granulator rotors, heat at the edge | Corrosive washdown, food contact |
| SKD11 / DC53 | JIS G4404, DIN 1.2379 modified | 58–62 | Thin blades ≤ 2 mm, fine carbide distribution, tighter tolerances | Bulk abrasive shredding |
| Tungsten carbide | ISO 513, K10–K20 grade | HRA 89–92 | Abrasive composites, fibre-reinforced polymers, long intervals | Impact-loaded applications, low RPM |
| 420 / 440C stainless | ASTM A276, EN 1.4125 | 50–58 | Food, pharma, washdown environments | High-volume abrasive cutting |
| PVD-coated (TiN, TiCN, CrN, DLC) | ISO 14574 (coating classification) | Substrate + coating | Adhesive build-up, friction-sensitive cuts, interval extension 2–4× | Re-sharpening frequency too high to justify coating cost |
Standard tolerances: ± 0.01 mm on critical dimensions, ± 0.05 mm on non-critical, surface roughness ≤ Ra 0.4 µm unless otherwise specified. Material grades cited perASTM A681,ISO 9001:2015,ISO 22514-2 (Cpk), andJIS G4404 / SKD11.
Our Method
A proprietary 30-minute framework our engineering team runs on every inquiry, evaluating each application across five dimensions. We specify the cut, not the steel — the grade falls out of the first four dimensions. Full breakdown published in our engineering notebook.
Factor 1: Substrate — what is being cut
The substrate dictates the wear mechanism, the contamination tolerance and (in food or pharma) the regulatory class. We classify into six families: paper and tissue, film and foil, food and pharma, plastics, recycled feedstock, metal. We do not quote until substrate is pinned down — a D2 blade that lasts 90 days on paper will last 9 days on glass-filled PA66.
Factor 2: Geometry — what shape the knife takes
Circular, straight, serrated, shear, granulator, or custom profile. Geometry is determined by the machine, not the cut — but interacts with substrate through chip flow and clearance angle. A 30° clearance that works for paper will chip on recycled polymer; a 12° clearance that survives recycled polymer will smear on paper. Roughly 40 % of our orders are custom geometry.
Factor 3: Hardness target — the operating window
HRC 58–62 is correct for ~70 % of applications. The remaining 30 % splits between too soft (recycling, abrasive composites) and too brittle (thin blades, shock-loaded rotors). We specify hardness as a numeric range against an equivalent standard (ASTM A681, A600, A276, ISO 513, JIS SKD11) — never as a verbal "hard" or "extra hard".
Factor 4: Edge preparation — honed, sharp, or micro-honed
The most under-specified variable and the one most often blamed for "the steel is wrong" when it is actually the grind. Three families: sharp (< 5 μm, paper / film), light hone (5–25 μm, general converting), micro-hone (25–75 μm, recycled feedstock). We specify edge prep as a numeric radius, not "slightly honed".
Factor 5: Operating speed and environment
At 600 m/min on film, edge temperature reaches 200–300 °C — D2 loses hardness above 200 °C; M2 holds to 600 °C. Above 1,500 RPM on circular blades, balance grade matters. Washdown environments need stainless. PVD coatings (TiN, TiCN, CrN, DLC) extend interval 2–4× but only when substrate and edge prep are correct. A spec without line speed is a guess, not a specification.
Want the full 2,000-word engineering write-up, decision matrix, and a real case study?Read the KAIPU 5-Factor Framework →
Material Guide
Material selection drives edge retention, corrosion behaviour and total cost per cut. We specify deliberately rather than by default.
Step 1: D2 Tool Steel (1.2379)
High-chromium cold-work steel. Hardened to HRC 58–62, used for paper, film and general industrial cutting where wear resistance matters more than impact toughness.
Step 2: M2 High Speed Steel (1.3343)
Tungsten-molybdenum HSS with red-hardness up to 600 °C. Selected for high-speed slitting, granulator rotors and applications where heat builds up at the cutting edge.
Step 3: SKD11 / DC53
Japanese cold-work grades with finer carbide distribution than D2. DC53 offers higher toughness for thin blades that would otherwise chip.
Step 4: Tungsten Carbide
Cemented carbide tipped or solid. Used for abrasive composites, fibre-reinforced materials, and any cut where downtime for re-sharpening is the dominant cost.
Step 5: 420 / 440C Stainless
Martensitic stainless grades for food processing, pharmaceutical and washdown environments. Hardened to HRC 50–58 with good corrosion resistance.
Step 6: Coatings — TiN, TiCN, CrN, DLC
PVD coatings reduce friction, repel adhesive build-up and extend interval between sharpening by 2–4× depending on substrate and cut.
Engagement Process
Six documented stages. Every order carries an engineering review before any steel is cut, and a CMM-traceable inspection before any blade ships.
Step 1: Drawing or sample submission
Send a 2D drawing (DXF, PDF, DWG), a 3D model (STEP, IGES, Parasolid, SolidWorks) or a worn sample. We accept partial information — a hand sketch plus the substrate and one operating parameter is enough to quote.
Step 2: Application review (within 1 business day)
Our engineering team reviews geometry, material, hardness target and operating speed. We respond with a specification, indicative price and lead time. If the drawing is unworkable we will say so, with the reason.
Step 3: DFMA confirmation
For new geometries we confirm grind direction, edge prep (honed vs. sharp), corner radii and any feature that affects manufacturing yield. This step locks risk before tooling is committed.
Step 4: Production with in-process inspection
CNC machining, vacuum heat treatment (in-house), optional PVD coating, final grind and edge prep. Hardness verified on every batch. First-article inspection archived for ten years per ISO 9001.
Step 5: Final CMM inspection and report
Coordinate measuring machine (Zeiss), optical comparator and surface roughness tester on critical dimensions. A digital inspection report is issued with every shipment. Non-conforming parts are scrapped — not reworked in secret.
Step 6: Dispatch and after-sales support
Standard lead time 15–25 business days from drawing confirmation. Express 7–10 days available on selected materials. Re-sharpening, recoating and replacement service available throughout blade life.
Risk and warranty
Frequently Asked
The eight questions our sales engineers hear most often. If yours is not here, email engineering and we will respond within one business day.
2D: DXF, DWG, PDF. 3D: STEP, IGES, Parasolid, SolidWorks, CATIA, NX. We can also work from a hand-drawn sketch, a worn sample, or a description of the application. If you only have a competitor’s part number, send that too — we will cross-reference it.
For custom geometries there is no formal MOQ. We routinely produce single pieces for trials and short production runs of 3–10 pieces. For standard catalogue parts the minimum is typically 1 piece.
Standard custom blades: 15–25 business days from drawing confirmation. Express 7–10 business days is available on selected materials (D2, M2, SKD11) and geometries that do not require new tooling. Re-sharpening and recoating: 5–7 business days.
Standard: ± 0.01 mm on critical dimensions, ± 0.05 mm on non-critical. Surface roughness: ≤ Ra 0.4 µm on the working edge, ≤ Ra 0.8 µm on ground surfaces. Flatness and parallelism verified on a granite plate. Tighter tolerances quoted per drawing.
Yes. Send the worn blade and we will return it sharpened, recoated if requested, and inspected. Typical cycle: 5–7 business days. We archive the geometry so repeat orders skip the engineering review.
ISO 9001:2015 certified since 2001. Last surveillance audit completed in 2026. Certificate, quality manual and a sample CMM inspection report are available on request. AS9100 readiness is in progress for aerospace customers.
D2 (1.2379 / SKD11), M2 HSS (1.3343 / SKH51), DC53, tungsten carbide K10–K20, 420 and 440C stainless are all held in stock as raw bar and plate. Exotic grades (ASP® 2023, CPM® 10V, Vanadis 4 Extra) are sourced on request.
Yes. KAIPU exports to converters, recyclers and OEMs across four continents — North America, Europe, Latin America and Asia-Pacific. We ship EXW, FOB, CIF and DDP. Standard packing is vacuum-sealed foil + foam + plywood crate suitable for ocean freight.
Send us the part, the application notes, or just the symptoms. We will respond with a specification, a quote and a lead time — typically within one business day. Last reviewed: 2026.