S5

Data verified

S5 uses about 2% silicon to reach exceptional toughness — in classic tool steel comparisons it tops the shock-resistance chart. It is chosen for the most violent impact tools in the shop.

Hardness52–59 HRC

DIN— (1.2419 family, near)

AISIS5

CategoryTool Steel

Chemical composition

Element	Content (%)
C	0.50–0.65
Si	1.75–2.25
Mn	0.60–1.00
Mo	0.20–0.40

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

Properties

Delivery condition	Annealed
Hardness (hardened)	52–59 HRC
Density	7.85 g/cm³
Toughness	Among the highest of all tool steels

Heat treatment

Harden 870–930 °C oil; temper 200–540 °C to balance hardness against impact.

Equivalent grades

Standard	Designation
din	— (1.2419 family, near)
aisi	S5

Compare side by side: S5 vs S2 · S5 vs S7

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

Applications & Processing

Applications: Heavy chisels, shear blades, clutch teeth, gripper dies, pneumatic tools, swaging dies.

Processing: Oil hardening in moderate sections; decarburization protection matters because of the high silicon.

Need S5 from stock?

Steel.Wiki is sponsored by Shenzhen NewAsia Special Steel (Nasteel), a special-steel stockholder in Shenzhen stocking mold, tool and alloy steels with EN 10204 3.1 certification.

Ask for a quotation Visit Nasteel

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.