Tool Steel Grades and Suppliers for Peoria, IL Tool Rooms and Die Shops

It depends on volume and how much shock the die sees. D2 is the high-wear specialist: with roughly 12% chromium and high carbon, it carries a heavy carbide load that resists abrasion exceptionally well, so it is the right pick for very long production runs on thinner sheet where edge wear is the failure mode. The cost is toughness, because D2 is comparatively brittle and prone to chipping if the die takes impact or works thick, tough material. A2 is the safer all-around choice: it air-hardens with minimal distortion, holds 57 to 62 HRC, and offers a much better balance of toughness and wear resistance, which makes it the better option for dies on heavier plate or where some shock is unavoidable. A practical rule for Peoria shops is to default to A2 unless you are running high enough volume that wear, not chipping, is clearly the limiting factor, in which case D2's longer edge life justifies its brittleness. When in doubt, A2 costs you less in cracked-die surprises.

H13 is the standard answer and for good reason. Its chromium-molybdenum-vanadium chemistry is specifically engineered to resist softening, thermal fatigue, and heat checking at elevated temperature, which are the dominant failure modes in forging and die-casting tooling. Run at roughly 44 to 52 HRC, H13 deliberately gives up peak hardness in exchange for the toughness and thermal stability needed to survive cyclic red-hot loading without cracking. For Peoria's forging and die-casting suppliers making heavy-equipment components, H13 is the baseline hot-work grade, and its excellent resistance to thermal fatigue is the reason it dominates the category. To get full life from H13 tooling, pay close attention to heat treatment and tempering, since hitting the right hardness-toughness balance is what keeps the die from heat-checking early. Surface treatments such as nitriding can further extend life on high-wear forging surfaces. If your tool runs cold rather than hot, H13 is the wrong choice and you should look at A2, D2, or S7 instead depending on whether wear or impact governs.

Reach for S7 whenever impact is the enemy. S7 is a shock-resisting grade built to absorb repeated heavy blows without chipping, which is exactly where wear-focused grades like D2 fail and where even A2 can struggle. Punches, chisels, shear blades, and any tool that hammers or shears thick material are classic S7 applications. It air-hardens to about 54 to 56 HRC with excellent toughness, trading peak wear resistance for impact survival. The decision really comes down to diagnosing the failure mode: if your tooling is chipping, cracking, or breaking under shock loads, S7 is the answer; if it is wearing smooth and losing edge geometry from abrasion, a cold-work grade like D2 or A2 will last longer. In Peoria's heavy-fabrication environment, S7 earns its place on tools that pound or shear heavy plate, where toughness matters far more than maximum hardness. Many tool rooms keep all of these grades in stock precisely so they can match the steel to whether the job is an impact problem or a wear problem.

It is as important as the grade itself, and it is where many tooling jobs quietly fail. A tool steel reaches its rated hardness, toughness, and dimensional stability only when it is austenitized at the correct temperature, quenched in the right medium, and tempered on the proper cycle, and any deviation costs you one of those properties. A2 and D2 air-harden with low distortion, which is part of why they suit precision dies; O1 oil-quenches with more movement and so suits simpler shapes; H13 and S7 demand careful tempering to reach their toughness targets. Peoria's tooling ecosystem includes commercial heat-treat houses experienced with all five common grades, and you should treat heat treat as part of the specification rather than an afterthought. Specify target hardness, allowable distortion, and any surface treatments like nitriding, and confirm your treater can document the cycle and verify final hardness. For critical tooling, vacuum hardening plus proper stress relief between rough and finish machining pays for itself in stability and tool life. A mis-treated die costs far more than the steel when it fails mid-production.

Yes, O1 remains genuinely useful, especially for tool rooms that value simplicity and fast turnaround. O1 is an oil-hardening grade that machines easily in the annealed state, hardens at lower temperatures than air-hardening steels, and reaches a solid 58 to 62 HRC, which makes it an excellent choice for low-to-moderate-volume tooling, gauges, and form tools where predictability matters more than maximum production life. Its main limitation is distortion: oil quenching introduces more dimensional movement than the air hardening of A2 or D2, so O1 is best suited to simpler geometries and shorter runs where that movement is manageable. For a Peoria tool room building a one-off form tool, a gauge, or a short-run die, O1 is often the most economical and convenient choice precisely because it is forgiving to machine and quick to heat treat. You step up to A2 when you need lower distortion on a more complex or precise die, and to D2 when wear life on a long run becomes the priority. O1's continued popularity reflects that not every job needs an air-hardening steel.