1.2085 Steel: Full Guide to Properties & Material Selection

Its DIN code is X33CrS16, a martensitic anti-corrosion mold steel with stable performance.

Carbon is controlled at 0.28–0.38%, and chromium hits 15.0–17.0%. High chromium forms a tight chromium oxide protective film, so it works well with corrosive plastic and in damp workshops.

Its biggest difference from other anti-rust mold steel is extra sulfur (0.05–0.10%). This small sulfur addition lifts cutting speed by around 30% vs 1.2316, cutting down machining hours and cutter costs for mass mold production.

Silicon and manganese each stay ≤1.00%, phosphorus strictly limited below 0.030% to guarantee clean steel.

This tool steel ships in pre-hardened state as standard, with factory hardness 280–325 HB, equal to 28–34 HRC.

This hardness range is well balanced: hard enough to stop wear and shape shift during injection molding, yet soft enough for fast milling, drilling and tapping.

For mechanical figures in pre-hardened stock: tensile strength ≥1100 MPa, yield strength ≥905 MPa, elongation after break ≥10%. It is neither too brittle nor too soft, with perfect balance of strength and flexibility.

For jobs needing harder material, you can quench it to roughly 48 HRC, but most mold shops use the ready pre-hardened grade directly.

Standard mold steel production line from ingot to finished product:

Medium frequency furnace melting & alloy mixing → LF furnace refining to remove solid impurities → VD vacuum degassing to remove gas impurities → ingot casting → forging (3-upset-3-draw for thick plates) → stress-release annealing → pre-hardening tempering to hit 280–325 HB → inspection & storage.

Minimum forging ratio is 4, to fully break big crystal branches inside raw ingots. Plates thicker than 200mm must go through repeated upset and draw steps.

ESR electroslag remelting is an optional upgrade step. DIN 1.2085 rules require tight control over all steps to keep steady quality for every steel block.

It mainly serves plastic mold making, with best performance when molding corrosive plastic.

PVC injection molds are its top use. PVC releases weak hydrochloric acid under high heat, which creates rust pits quickly on regular mold steel. Its 16% chromium content blocks this chemical corrosion well.

Other ideal jobs: food industry molds touching acid materials, high-gloss car interior injection molds, medical plastic part molds that need anti-rust ability.

These two are top anti-corrosion plastic mold steel choices, sharing nearly the same 16% chromium martensitic stainless base. The only gap is sulfur content in 1.2085.

Picking 1.2085 tool steel means faster cutting and longer cutter life, its main selling point vs 1.2316.

Picking 1.2316 means cleaner steel and better polishing finish.

If your factory makes high annual mold output and changes cutters often, 1.2085 delivers much better cost performance.