ASTM H12 Tool Steel | 1.2605 | X35CrWMoV5 | SKD62 | BH12

ASTM H12 Tool Steel | 1.2605 | X35CrWMoV5 | SKD62 | BH12 2016-12-04T15:43:09+00:00

Project Description

For hot works tool steels application, we could supply some common tool steels, like H10 steel, H11 steel and H13 steel, and we could also supply AISI h12 tool steel materials for your hot works applications.

AISI h12 tool steel is a 4.75~5.5% chromium, general-purpose hot work steel. H12 tool steel contains (0.2~0.5%) less vanadium than the widely-used H13 hot works tool steel (0.8~1.2%). ASTM/AISI H12 Steel is a deep-hardening, air-hardening steel that exhibits minimal size change during heat treatmnet. H12 tool steel material has good resistance to thermal fatique cracking (heat cracking) and excellent resistnce to gross cracking and thermal shock when water cooled in service. So, we could say H-12 tool steel mainly has the following characteristics:

  • Excellent resistance to wear, high strength at elevated temperature.
  • Good homogenizing with high toughness.
  • Extra- fine- structure without grain-boundary carbide.
  • Inclusion shape controlled with high cleanliness.

aisi astm h12 tool steel hot work

1.ASTM H12 Tool Steel Supply Range

H-12 Steels Bar: diameter 8mm–1000mm
H12 Steel Flat: thickness 16-500mm x width 200-800mm
H12 Steels Plate: thickness 16-500mm x width 200-810mm
Other dimension according to your requirements

Surface Finish: Black, Rough Machined, Peeled, Turned or as per given requirements.

2.AISI H12 Tool Steels Standard and Relevant Steel Specifications

Country USA German Japan British
Standard ASTM A681 DIN EN ISO 4957 JIS G4404 BS 4659
Grades H12/T20812 1.2605/X35CrWMoV5 SKD62 BH12

3.H12 Tool Steel and Equivalent Chemical Composition

ASTM A681 C Mn P S Si Cr V W Mo Ni Cu Sn
H12/T20812 0.30 0.40 0.20 0.60 0.03 0.03 0.80 1.25 4.75 5.50 0.20 0.50 1.00 1.70 1.25 1.75
DIN ISO 4957 C Mn P S Si Cr V W Mo
1.2605/X35CrWMoV5 0.32 0.40 0.20 0.50 0.03 0.02 0.80 1.20 4.75 5.50 0.20 0.50 1.10 1.60 1.25 1.60
JIS G4404 C Mn P S Si Cr V W Mo
SKD62 0.32 0.40 0.20 0.50 0.03 0.02 0.80 1.20 4.50 5.50 0.20 0.50 1.00 1.60 1.00 1.60
BS 4659 C Mn P S Si Cr V W Mo
BH12 0.30 0.40 0.40 0.35 0.35 0.85 1.15 4.75 5.25 0.50 1.25 1.75 1.25 1.75 0.40 0.20 0.05

4. H12 Hot Work Tool Steel Mechanical Properties

  • Modulus of elasticity [103 x N/mm2]: 207
  • Density [g/cm3]: 7.84
  • Thermal conductivity [W/m.K]: 18.9

Coefficient of Linear Thermal Expansion 10-6 oC-1

20-100oC 20-200oC 20-400oC 20-600oC
9.8 11 12.1 13

5. Forging of H12 Tool Steel

Hot forming temperature: 1100-850oC.

6. H12 Tool Steel Heat Treatment


Heating Steel H-12 slowly and uniformly to 845~900℃, furnace cooling to 540℃ at a rate 10~20℃/hr. Hardness HB 229 max

Stress Relieving

Stress relieving to remove machining stresses should be carried out by heating H12 steel to approx.650oC, holding for 1-2 hours at heat, followed by air cooling. This operation is performed to reduce distortion during heat treatment.


  • Preheating (1): Heat H-12 steel to approx. 540~650℃, holding 30 minutes per 25mm.
  • Preheating (2): Heat H12 tool steels to approx. 845~870℃, holding 30 minutes per 25mm.
  • Austenitizing: Heat steel H12 to approx. 1010~1050℃, holding 30 minutes per 25 mm.
  • Quenchant: By oil or air.


Tempering temperature: 520-700oC, hold at least 2 hours, air cooling and double tempering.

7.Applications of AISI H12 Tool Steel

AISI H12 hot work tool steel is usually used for hot tooling applications where maximum resistance to cracking is required. Such typical applications include the following:

  • Extrusion indushry: dies and inner liner for extrusion, extrusion tools
  • Forging Industry: forming dies, press dies
  • Die casting industry: dies for die-carbide
  • Tool Industry: hot punch, hot shear blades, immediate roller for cold rolling

Otai steel is one leading supplier and exporter of H12 tool steel, H10/SKD7 tool steels, H13/SKD61 materials for your hot works tools uses. You please feel free to contact us for any of your requests. We are a better choice for you.