What is D2 Steel?

What is D2 steel? Simply put, D2 steel material is a high‑carbon high‑chromium cold‑work tool steel. In industry, it is often called “air‑hardening steel”. It can harden when cooled in open air. Its common international grades include AISI D2 from the US, SKD11 from Japan, and 1.2379 from Germany.

 

When it comes to chemical composition, its carbon content ranges from 1.40% to 1.60%. Its chromium content is between 11.00% and 13.00%. Besides, molybdenum, vanadium and other alloying elements are added. These elements refine grain size and boost overall mechanical properties.

 

With proper heat treatment, its hardness can steadily hit 58‑65 HRC. As a result, it delivers excellent wear resistance and compressive strength. Thanks to high chromium content, it also gains certain atmospheric corrosion resistance. What is more, it shows very little dimensional change during heat treatment. For this reason, it fits well for parts requiring high dimensional accuracy.

 

Due to this well‑balanced set of outstanding properties, D2 tool steel gets wide‑ranging uses. It is widely used for long‑life precision dies such as blanking dies, cold extrusion dies and drawing dies. Meanwhile, it is heavily adopted for high‑performance cutting tools, industrial blades, thread rolling plates and precision gauges. It plays a vital role in die‑making and mechanical processing fields.