SKD61/H13 is the general default with better availability and polish response. SKD7 (H10 type) is picked for very high hot-strength duty — heavy forging and copper-alloy extrusion — where its Mo-rich chemistry holds hardness longer.

Grades · Tool Steel · SKD7

SKD7

Data under review

SKD7 is a JIS hot work tool steel of the 3% Cr–3% Mo–V type, the near counterpart of AISI H10. Its molybdenum-rich chemistry trades some of the 5% Cr grades’ oxidation margin for high hot strength and resistance to heat checking in forging and extrusion service.

Hardness44–52 HRC

DIN1.2365 (32CrMoV12-28, near)

AISIH10 (near)

JISSKD7 (JIS G4404)

CategoryTool Steel

Chemical composition

Element	Content (%)
C	0.28–0.35
Si	≤0.50
Mn	≤0.60
P	≤0.030
S	≤0.020
Cr	2.70–3.20
Mo	2.50–3.00
V	0.40–0.70

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

Properties

Delivery condition	Annealed
Working hardness	44–52 HRC
Density	7.80 g/cm³
Hot hardness	Good to ≈550 °C

Heat treatment

Harden 1010–1050 °C air/oil; double temper 550–620 °C to working hardness.

Equivalent grades

Standard	Designation
din	1.2365 (32CrMoV12-28, near)
aisi	H10 (near)
jis	SKD7 (JIS G4404)
gb	3Cr3Mo3V (near)

Compare side by side: SKD7 vs H10

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

Applications & Processing

Applications: Hot forging dies and inserts, extrusion dies and dummy blocks, hot shear blades, brass/copper extrusion tooling.

Processing: Air or oil hardening with low distortion; ESR quality preferred for large dies. Nitriding is used cautiously (brittle case risk at high Mo).

FAQ

SKD7 or SKD61 (H13)?: SKD61/H13 is the general default with better availability and polish response. SKD7 (H10 type) is picked for very high hot-strength duty — heavy forging and copper-alloy extrusion — where its Mo-rich chemistry holds hardness longer.

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Source: JIS G4404 published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.