H-11
H-11 Grade Introduction:
Chromium hot-work tool steels are designated as group H steels according to the AISI classification system. This series of steels start from H1 to H19. The most commonly used chromium hot-work steels are H11, H12, and H13, which can be air-hardened in 150 mm thick sections. The steels are subjected to minimal distortion during hardening due to their balanced alloy content. The tools produced from chromium hot-work steels can be cooled using water without damage as these steels have low carbon and alloy contents.
H-11 Grade Application:
- Highly stressed structural parts such as aircraft landing gear
- Hot punches
- Die casting dies
- Forging dies
- Hot shear blades
- Hot gripper dies
H-11 Equivalent Grades:
| Country |
USA |
German |
Japan |
British |
| Standard |
ASTM A681 |
DIN EN ISO 4957 |
JIS G4404 |
BS 4659 |
| Grades |
H11/T20811 |
1.2343/X37CrMoV5-1 |
SKD6 |
BH11 |
H-11 Chemical Composition:
| Element |
C |
Si |
Mn |
P |
S |
Cr |
Mo |
Ni |
V |
Cu |
Fe |
| Content (%) |
0.33-0.43 |
0.80-1.20 |
0.20-0.50 |
0.03 |
0.03 |
4.75-5.50 |
1.10-1.60 |
0.3 |
0.30-0.60 |
0.25 |
Balance |
Mechanical Properties:
| Property |
Imperial |
Metric |
| Tensile Strength |
260 ksi |
1792 MPa |
| Tensile Strength, Yield (0.2% Offset) |
215 ksi |
1482 MPa |
| Individual Value |
6% |
6% |
| Average Value |
15% |
15% |
Physical Properties:
| Properties |
Metric |
Imperial |
| Density |
7.81 g/cm3 |
0.282 lb/in3 |
| Melting point |
1427°C |
2600°F |
Thermal Properties:
| Properties |
Metric |
Imperial |
| Thermal expansion (@20-100ºC/68-212ºF) |
11.9 x 10-6/ºC |
6.63 µin/in°F |
| Thermal conductivity (@100ºC/212ºF) |
42.2 W/mK |
292.9 BTU in/hr.ft².°F |
Forging Properties:
H11 tool steels are forged at 1121°C (2050°F). For this type of steels, forging below 899°C (1650°F) is not preferable.
Stress Relieving:
Stress relieving after rough machining, stress in the tool can be released by heating at 650°C during 2 hours followed by air cooling.