Blade-grade strip that blanks into an industrial knife, utility blade or saw body, hardens to 55–62 HRC, and holds an edge through millions of cuts — with flatness and decarb controlled on paper before the blade ever enters the furnace.
Every cutting blade solves the same triangle: edge hardness (how long it stays sharp), toughness (how it resists chipping under load), and corrosion resistance (whether it survives the environment). No single steel wins all three. The four families below are how blade engineers pick the corner of the triangle their part lives in.
C 0.80–0.95%. The hardest, most wear-resistant blade steel available without alloy additions. SK85 and SK95 reach 60–62 HRC for maximum edge life on industrial cutting blades and razor stock. SK5 and SK7 trade a little hardness for toughness on utility knives and impact-duty blades.
Choose carbon tool steel when edge life is the priority and corrosion is controlled.C 0.36–0.45% + Cr 12–14%. Hardens to 52–56 HRC and resists rust, food acids and wash-down chemicals. The standard for food machinery slicing blades, kitchen knives and medical instruments where the blade cannot stain or corrode in service.
Choose martensitic stainless when the blade sees moisture, food or medical environments.C ≤0.15%, Cr 16–18%, Ni 6–8%. Does not quench-harden; instead work-hardens during blanking and grinding, reaching 40–50 HRC at the edge. Used for ultra-thin flexible blades — razor blades, surgical scalpels, film slitting blades — where the blade must flex without breaking.
Choose SUS301 for thin, flexible blades that bend rather than stay rigid.C 0.72–0.80% + Cr 0.30–0.60%. The European standard for circular saw blade bodies and heavy cutting plates. Chromium improves hardenability and tightens the hardness band across large-diameter plates (100–500 mm OD), so the body hardens uniformly from bore to rim.
Choose 75Cr1 for saw blade bodies and large plates where hardness uniformity matters.Indicative values from production blade programs; the final spec is agreed at RFQ against your blade geometry, cutting duty and governing standard.
| Parameter | Typical value | Why it matters |
|---|---|---|
| Strip thickness | 0.10 – 2.5 mm | Razor and surgical blades run 0.10–0.30 mm; utility blades 0.5–1.0 mm; saw blade bodies 1.2–2.5 mm |
| Delivery condition | Spheroidized (standard) / H&T (on request) | Spheroidized blanks cleanly and hardens predictably; H&T delivers edge hardness with the material for thin blades |
| Finished blade hardness | 55 – 62 HRC (carbon tool) / 52 – 56 HRC (mart. stainless) | Sets edge retention vs. chipping resistance — the central trade-off in every blade design |
| Flatness | ≤ 0.15 mm/m (before blanking) | Flat strip in = flat blade out; wavy strip cannot be ground true after hardening without excessive stock removal |
| Decarburization | ≤ 0.03 mm per side (controlled anneal) | A decarburized skin under-hardens and rolls over instead of cutting; critical for blades not fully surface-ground |
| Saw blade body geometry | Thickness 1.2–2.5 mm, OD 100–500 mm | Defines the centrifugal and cutting load the body must resist at operating speed |
| HSS saw blade linear speed | 60 – 80 m/s | Sets the thermal and stress envelope for the blade body; the body must stay true and fatigue-resistant at this speed |
| Surface finish | Clean, scale-free, oiled or dry per order | Blanking, laser cutting and edge grinding all require a consistent, defect-free surface |
| MTC | Chemistry + mechanicals + decarb + flatness per heat | Traceability for blade certification, customer audits and regulatory compliance (food, medical) |
Hardness, flatness and decarb are agreed per order and verified on the inspection report. For hardened-and-tempered delivery (thin-gauge razor and surgical blades), the HRC band is confirmed per coil.
All supplied spheroidized as standard, hardened-and-tempered on request. The choice is blade type, environment, and whether you are on a JIS, GB, AISI or EN drawing standard.
| Grade | Family | Typical hardness (after Q&T) | Typical blade use |
|---|---|---|---|
| SK5 (JIS) | Carbon tool steel | 57 – 60 HRC | Utility knife blades, industrial cutting blades, general-purpose knives |
| SK7 (JIS) | Carbon tool steel | 55 – 58 HRC | Impact-duty blades, chisels, scrapers, medium-duty cutting tools |
| SK85 / SK95 (JIS) | Carbon tool steel | 60 – 62 HRC | Razor blades, surgical blades, high-wear industrial slicing blades |
| 4Cr13 (GB) | Martensitic stainless | 52 – 56 HRC | Food machinery slicing blades, kitchen knives, medical instruments |
| SUS420J2 (JIS) | Martensitic stainless | 50 – 54 HRC | Corrosion-resistant utility blades, marine cutting tools, food processing |
| SUS301 (JIS) | Austenitic stainless | 40 – 50 HRC (work-hardened) | Ultra-thin flexible razor blades, surgical scalpels, film slitting blades |
| 75Cr1 (EN) | Alloy tool steel | 55 – 59 HRC | Circular saw blade bodies (100–500 mm OD), heavy cutting plates |
Hardness values are typical after standard quenching and tempering; the exact band depends on section thickness and tempering temperature. Confirm the delivered heat on the MTC. SK85/SK95 and SUS420J2 values are indicative of their respective standard families — refer to the latest revision for governing limits.
These are the failure modes that show up in blade production, in the order blade engineers care about them.
A decarburized surface under-hardens; the edge rolls over instead of shearing the workpiece. Fix: controlled-atmosphere spheroidizing with measured decarb ≤ 0.03 mm per side, reported on the certificate. Critical for blades hardened without full surface grinding.
Strip with internal flatness scatter comes out of the quench furnace with permanent wave that cannot be ground out without removing excessive stock. Fix: tight flatness on the delivered strip (≤ 0.15 mm/m) and uniform gauge so the quench cools the blade symmetrically.
Blades that are too hard for the cutting duty chip at the edge; blades that are too soft roll. Fix: grade selection matched to duty — SK5/SK7 for impact cutting, SK85 for high-wear slicing, 4Cr13 for corrosion environments — and a tempering cycle that lands in the correct HRC band.
On 300–500 mm OD saw bodies, lean carbon steels can run soft at the rim where the quench is slower. Fix: 75Cr1 with chromium for deeper hardenability, or a confirmed hardenability band on the carbon steel grade so the body hardens uniformly from bore to rim.
Blade production draws on several steel families. Match your product below and confirm at RFQ.
SK5 / SK7 / SK85 carbon tool steel and 75Cr1 alloy tool steel for industrial cutting blades, utility knives and saw blade bodies — the core of this page. Tool steel family →
4Cr13 / SUS420J2 for food machinery blades, kitchen knives and medical instruments where corrosion resistance is non-negotiable. Martensitic stainless family →
SUS301 austenitic stainless for ultra-thin flexible razor blades, surgical scalpels and film slitting blades that work-harden at the edge. Stainless steel family →
SAE1078 / SAE1074 for saw blade bodies and heavy cutting plates where the carbon ceiling is lower and toughness is prioritized. High carbon family →
A typical food-grade rotary slicing blade, described the way it runs.
The blade is a 250 mm OD disc, 1.5 mm thick, with a 40 mm bore and a continuous scalloped cutting edge ground around the rim. The drawing calls 4Cr13 martensitic stainless strip, 1.5 mm, spheroidized, flatness ≤ 0.15 mm/m, decarb ≤ 0.03 mm per side. The coil is blanked — laser for the profile and bore — then the blades go through austenitizing at 1020–1050 °C, oil quenching, and tempering to 52–54 HRC. After hardening, the cutting edge is ground to a 15° included angle, the faces are polished to a 0.4 μm Ra for food contact, and the blade is passivated to seal the stainless surface.
The passivation bath is the moment of truth: any decarburized skin or surface defect from the strip shows up as a rust spot after passivation, and the blade is scrapped. That is why the strip's decarb limit and surface condition are not optional — they are the difference between a 98% first-pass yield and a 70% yield with rework. Our job is to make the strip's flatness, decarb and surface so repeatable that the blade line's variables are the only variables left.
If your blade sits in the 0.10–2.5 mm envelope across any of the four families, send the drawing and we confirm grade, flatness, decarb limit and a trial-coil plan. Our slitting and processing services cover exact-width coils, cut-to-length sheets and edge conditioning for blanking or laser nesting.
Related reading: what spheroidizing annealing does to carbide structure in tool steel, and how surface finish and decarb interact on hardened blade edges. For a broader view of procurement, see our precision steel strip buyer's handbook.
These grade families share material, processing or application territory with the topic on this page.
SK5 / SK7 / T8A / T10A grades with wear resistance and edge hardness for cutting tools.
4Cr13 / 2Cr13 / SUS420 grades with corrosion resistance and hardenability for food and medical blades.
SAE1078 / 65Mn / SK5 grades for saw blade bodies, cutting edges and hardened components.
Send thickness × width, blade type, target HRC, quantity and destination port. Our engineers reply within one working day with grade match, flatness/decarb confirmation and a trial-coil option.