H23

Data under review

H23 pairs about 12% chromium with 12% tungsten for hot work at the top of the temperature range, where oxidation and softening defeat lower-alloy dies. It is a niche grade for the hottest extrusion and forging contact surfaces.

Hardness35–45 HRC

AISIH23

CategoryTool Steel

Chemical composition

Element	Content (%)
C	0.25–0.35
Si	0.15–0.60
Mn	0.15–0.40
Cr	11.00–12.75
W	11.00–12.75
V	0.75–1.25

Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.

Properties

Delivery condition	Annealed
Working hardness	35–45 HRC
Density	8.30 g/cm³

Heat treatment

Harden 1120–1200 °C air/oil; temper 600–700 °C, multiple tempers typical.

Equivalent grades

Standard	Designation
aisi	H23

Compare side by side: H23 vs H21 · H23 vs H19

Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.

Applications & Processing

Applications: Extrusion dies for copper alloys, hot forging die inserts, dummy blocks and liners for severe service.

Processing: Low toughness and difficult machining; use supported insert designs and careful preheating.

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Source: ASTM A681 published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.