H21 is a tungsten-alloyed hot-work tool steel designed for applications requiring good hot hardness and resistance to softening at elevated temperatures.
Chemical Composition
C
Si
Mn
Cr
W
V
0.25 – 0.35
0.15 – 0.30
0.20 – 0.40
2.50 – 2.80
8.50 – 10.00
0.30 – 0.40
Heat Treatment
Preheating
Austenitizing generally around 1150–1200°C
Controlled cooling
Double tempering according to required working hardness
Mechanical Properties
High hot hardness
Good resistance to temper softening
Good high-temperature strength
Typical working hardness generally around 40–50 HRC, depending on treatment
Equivalent Grades
AISI: H21
DIN: 1.2581
DIN: X30WCrV9
JIS: SKD5
Applications
Hot forging dies
Hot punches
Extrusion tooling
Die-casting tooling
Hot forming tools
Mandrels
Hot-working components operating at high temperature