Comparison
1.2379 vs 1.2363
The two cold-work steels are confused because both are alloy tool steels for punches and cutting tools. 1.2379 has more carbon and chromium – more carbides, higher wear resistance, more brittle. 1.2363 has less carbon – fewer carbides, better toughness, slightly less wear resistance. You choose by whether the tool wears out or breaks.
The short difference
1.2379 (X153CrMoV12, AISI D2, often Sverker 21 / K110) is the high-chromium D2 steel. 1.2363 (X100CrMoV5, AISI A2, often Rigor / K305) is air- or vacuum-hardening A2. Both are typically supplied soft annealed so you can mill, and hardened afterwards.
- 1.2379 – wear, cutting edges, long runs where the edge wears
- 1.2363 – toughness, tools that take impact or off-centre loads
- PM variants when conventionally melted D2 no longer holds up
Which to choose when
1.2379 when wear is what finishes the tool. 1.2363 when a D2 tool has cracked, or the workpiece strikes. It is not a stainless mould steel (1.2083) and not a hot-work steel (1.2344). We convert trade names to W.Nr. on the certificate when the mill can carry it.
Delivery
Flat and round, soft annealed, sawn. We do not invent a hardness you only get after hardening. Condition and certificate must be on the PO – especially if the drawing says Sverker, Rigor, K110 or K305.
Frequently asked questions
- Is 1.2379 the same as Sverker 21?
- Sverker 21 is Uddeholm's name in the D2 family. We write 1.2379 / X153CrMoV12 on the certificate when that is the material the mill supplies.
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Send your enquiry
State grade, dimensions and quantity — or attach a drawing. We reply with a quote.