Cutting Blade Material Guide: HSS vs D2 vs SKD11 vs Carbide
Same drawing, four steels, four different service lives. The right material is the one that matches how your blade fails.
The same drawing, cut from four different steels, will give you four different service lives — and the longest life is not automatically the right answer. A blade that is too hard for its job chips at the edge, and a chipped blade stops the line just as fast as a dull one. Material selection is about matching the steel to how the blade fails, not to a hardness number on a spec sheet.
These are the four families we grind most often, and the trade-offs between them.
The four materials at a glance
| Material | Typical hardness | Wear resistance | Toughness | Usually chosen for |
|---|---|---|---|---|
| HSS (SKH-51, M2, M35) | 62–68 HRC | Good | High | Fast, thin-stock cutting — mask machine blades, shear blades |
| D2 / SKD11 | 58–62 HRC | Very good | Medium | Long production runs, thicker stock, slitting and trimming |
| Stainless (420 / 440C type) | 52–58 HRC | Moderate | High | Food, pharma and wet environments where rust is the enemy |
| Solid carbide | ~88–92 HRA | Excellent | Low | Abrasive stock — composites, board, filled plastics |
Note the hardness scales: tool steels and stainless are quoted in HRC, carbide is normally quoted in HRA, which is a different scale. Do not compare an HRA figure with an HRC figure directly.
Choose by failure mode
- Edge dulls too fast? The material is not hard enough for the abrasive content of what you cut. Move up the wear-resistance column: HSS to D2, D2 to carbide.
- Edge chips or nicks? You are past the toughness limit. Move down the hardness column, or open the edge angle slightly so the cutting edge has more metal behind it. On a chipping problem, softer steel usually lasts longer than harder steel.
- Material sticks and builds up on the edge? That is a friction problem, not a hardness problem. A polished face and a coating will fix it faster than a material change.
- Rust or hygiene limits? Stainless is the answer even though it cuts less well — a rusted edge contaminates the product.
Coatings, briefly
TiN, TiCN, TiAlN and DLC coatings raise surface hardness and lower friction, which typically buys longer edge life and cleaner cuts on sticky materials. They do not rescue a blade whose geometry or base steel is wrong. We treat coating as the last step after the material and edge angle are right, not the first fix.
What we use for mask machine blades
For the thin, high-speed cutting on a mask line we grind SKH-51 imported high-speed steel, hardened to HRC 65–68. That hardness range is deliberately at the top of the HSS band: the stock is thin, the machine runs fast, and the blade has to stay sharp through a full shift rather than being replaced often. SKH-9 is the alternative where a little more toughness is wanted, and solid carbide is available where the material being cut is abrasive enough to justify it.
Sizes, thicknesses and the drawings for that range are on the mask machine blade page. For general converting work the same logic applies to circular knives, straight and bar knives and granulator and pelletizer knives.
Certificates and test reports
We do not publish certification claims on this site. If your buyer requires a specific standard, a material grade certificate or a hardness test report, tell us what is required with your enquiry and we will confirm in writing what we can document before you place an order — so there are no surprises at inspection.