The right tool-steel grade for an industrial knife depends on the material being cut, cutting action, machine geometry, clearance and required run length between sharpenings. An unsuitable grade can make a replacement blade wear, chip or deform differently from the original. Grade, heat treatment and delivered hardness must therefore be treated as separate parts of the specification.
The grade selection question, the short version
There are three main steel families, plus two common performance additions, that cover most industrial cutting applications:
Cold-work tool steels, including D2 / 1.2379 and other grades selected by application. BÖHLER K110 and Uddeholm Sverker 21 datasheets place D2-class application guidance within roughly 54–62 HRC depending on duty. This is producer guidance, not a universal delivered-blade specification.
High-speed steels such as M2 / 1.3343 and M42. They retain hardness at elevated cutting temperatures and are used where heat and abrasion make a cold-work grade unsuitable.
Powder-metallurgy (PM) tool steels. These are grade-specific materials for duties in which wear or edge stability dominates. CPM 10V / A11 and Vanadis 4 Extra are different families and must not be treated as interchangeable.
Tungsten-carbide (TC) tipping. Carbide provides very high wear resistance but is more brittle than tool steel. It is used where the application and blade geometry can justify that trade-off.
Coatings such as TiN, TiCN, CrN and DLC. They can change surface hardness, friction, corrosion behaviour and build-up, but they do not correct an unsuitable base grade or geometry.
Steel by application: how we actually choose
Tobacco primary and secondary
Cut-rag knives, tobacco-cutter knives, cigarette cut-off knives and filter knives are selected around edge stability, controlled hardness and run length between sharpenings. These knives are commonly offered in tungsten carbide, with M2 HSS and D2 as alternatives. Exact OEM grades and hardness values for KT-series drum and bottom knives are not publicly established, so the delivered specification must be determined from the drawing, worn sample and duty.
Paper and converting
Slitting, sheeting, perforation and guillotine blades are specified around edge quality, dust, edge rounding and chipping risk. Circular slitter and score knives are commonly offered in D2 or tungsten carbide, while guillotine-knife families include HSS, Cr-W-Mo tool steels, HSS inlays and carbide-tipped edges. Grade and hardness remain application-specific.
Wood — chipping, planing, peeling
Chipper and canter knives require a balance of impact resistance and wear. A8 Modified is an established chipper-knife steel; D2-class and carbide- or Stellite-tipped variants are also used depending on duty. Tersa-type planer systems are offered with HSS and solid-carbide options. Veneer knives use alloy tool steel, but exact grade and hardness vary by maker and application.
Metal — shearing, slitting, trimming
For rotary slitting, D2 / 1.2379 is commonly used for duties including copper, aluminium, thin cold-rolled steel and stainless, while HSS and tungsten carbide are used for more demanding applications. Plate-shear grades are selected by duty, with shock-resisting grades for impact-heavy cold work, D2-class grades for medium plate and non-ferrous material, and H13-class grades for hot shearing.
Recycling and plastics
Shredder, granulator and grinder knives must account for impact, abrasive feed and tramp-metal contamination. D2 / 1.2379 is common in granulator duty, while tougher cold-work grades such as DC53 and A8 are used where impact dominates. PM designations must be assessed as named grades against the actual feedstock rather than treated as a single material family.
Food
Food-cutting applications may require corrosion-resistant grades, finish requirements and food-contact documentation defined for the particular part and market. Grade, hardness and documentation cannot be inferred from the machine brand alone and must be confirmed for the order.
What "high-grade European tool steel" actually means
“High-grade European tool steel” is not a substitute for a material designation. Procurement should compare the named grade, governing standard and any material-documentation requirement stated in the quotation. A loose “equivalent” designation is insufficient where composition or heat-treatment response affects the part.
If the RFQ requires a pass-through mill certificate, state that requirement before ordering. Availability, certificate type and the identifiers to be connected to the order are then confirmed in the quotation.
What to verify at material intake
The incoming-material review should follow the order specification. Where these checks form part of the agreed scope, they may include:
Identification. Checking the supplied grade and, where required, the heat number against the order and available material paperwork.
Material-certificate review. Comparing the grade, heat number, chemical composition, delivery condition and declared standard with the ordered requirement.
Visual or dimensional checks. Reviewing bar or strip stock against the incoming specification where this forms part of the control plan.
A pass-through EN 10204 3.1 mill certificate may be available on request. It is not supplied automatically with every delivery. Include the requirement in the RFQ so that certificate availability and scope can be confirmed in the quotation.
Coatings and tipping — when to add them, when not
A coating or carbide tip is added when the steel alone cannot deliver the run length. It cannot compensate for an unsuitable grade. Common options are:
TiN / TiCN. These coatings can lower friction and increase surface hardness. Their temperature limits and suitability differ, so they must be selected for the duty rather than grouped as interchangeable options.
CrN. A tougher, corrosion-resistant coating used where humid or aggressive environments and anti-stick behaviour matter.
DLC. A low-friction coating family whose hardness and service-temperature limits depend on the specific DLC type and process.
Tungsten-carbide tipping. Used where high wear resistance justifies the cost and the application can tolerate carbide's lower toughness.
What to send if you want a quote on a specific blade
Send a drawing or dimensioned sketch and, where available, a worn sample of the blade currently running in the machine. Add the machine model, material being cut, line conditions, current service life and required quantity. The drawing defines the target geometry; the sample shows the chipping, wear and edge condition produced by the actual duty. Material, hardness and any documentation requirements are confirmed in the quotation.
Other posts in this series: how we run the production floor, how we inspect a finished blade, and what happens when you raise a complaint.