Tool Steel in Sheet Form: A Hardness Material in a Forming Process

Only in the annealed (soft) condition, and even then it is not a typical forming material. Tool steels are designed to be heat treated to high hardness, 55 to 62 HRC, for wear resistance, and in that hardened state they are brittle and will crack rather than bend. So you cannot fold a finished tool steel part on a press brake. The only workable path is to form or machine the part in the annealed condition and then heat treat it to final hardness, which means any bends must be minimal and done before hardening, and most flat tool steel parts have no bends at all, they are precision-ground plate. If your design needs a part that is both formed into a shape and hardened to tool-steel levels, that is a red flag that the design needs rethinking: either form a tougher steel and add a hardened wear insert, or split the part so only the wear-critical detail is tool steel. Trying to bend hardened tool steel produces cracked, scrapped parts, full stop.

Through a precision tooling workflow, not sheet metal fabrication. The typical sequence is: start from annealed tool steel plate, cut a blank (often by waterjet or saw because the stock is thick and to avoid heat effects), machine the features, heat treat to final hardness, then finish-grind to tolerance because heat treatment causes slight dimensional movement that grinding corrects. For intricate die details and blade profiles in fully hardened material, wire EDM is the key process: it cuts hardened tool steel with no mechanical force and no cracking risk, holding tolerances down to a few microns. This is why tool steel die plates, blanking dies, and precision blades come from tool-and-die shops and precision grinding/EDM houses, which have surface grinders, wire EDM machines, and heat-treat partnerships, rather than from a press-brake-and-laser sheet metal shop. The equipment and skills are genuinely different. If your part is a flat tool steel detail, source it from a precision tooling supplier, and ManufacturingBase can route you to shops with exactly that capability.

Match the grade to how the hardened part must perform, since all of them are heat treated rather than formed. A2 is the air-hardening general-purpose cold-work choice with good toughness and minimal heat-treat distortion, ideal for die plates and blanking dies. D2 is high-chromium and extremely wear-resistant for long-production-run blanking and forming dies, but it is more brittle, so avoid it where impact or thin sections invite chipping. O1 is oil-hardening, the easiest to machine and heat treat and the most economical, good for low-volume tooling and gauges. H13 is a hot-work grade built for thermal-fatigue resistance, the standard for die-casting and hot-forming tooling that cycles through heat. S7 is shock-resistant with high toughness, the pick for punches, chisels, and die details that take impact without chipping. The decision is about wear life, toughness, hardness, and heat-treat stability of the finished tool, not about formability, because none of these bend. Tell your supplier the application, production volume, and whether the part sees impact or heat, and they will recommend the grade and the heat-treat hardness target.

Clarify the real requirement first, because tool steel sheet metal is usually the wrong way to describe it. If you need a wear surface on a part that also has bends or formed features, the cleanest design is a formable steel base with a hardened tool-steel or tungsten-carbide wear insert mechanically fastened or bonded on, so the structure forms easily and only the contact point is hard. If you need a flat blade, die detail, or gauge, order it as a ground-and-hardened plate part from a tool-and-die or EDM shop, not as bent sheet. If you need a thin springy hardened component like a flapper or spring blade, hardened-and-tempered spring steel strip is usually the right material, formed soft and hardened afterward. The unifying principle is that hardness and forming do not coexist, so the part gets split or sequenced: form soft, harden after, or isolate the hard feature. Sharing the function, loads, and wear conditions with the supplier rather than just specifying tool steel sheet will get you a part that performs and costs far less than fighting the material in the wrong process.