AISI T4 tool steel is one of tungsten type high speed tool steel, which belongs to ASTM A600 specification, the standard for high speed tool steel materials.
ASTM T4 tool steel is similar to T1 Tool Steel materials, but with 4.25~5.75% cobalt added to increase heat resistance. The red hardness of T4 steel and the high temperature hardness is a little higher than T1 tool steel. AISI T4 tool steel is a deep hardening alloy capable of Rockwell C 64 hardness.
Otai Steel is one of the leading supplier of AISI/ASTM T4 tool steel high speed materials. We know the features of T4 high speed steel materials and different applications & your various applications. You have the T4 tool steel materials data below.
1.ASTM/AISI T4 Tool Steel Supply Range
T4 Steel Round Bar: diameter 2mm – 200mm
T4 Steels Flat: thickness 2-20mm x width 10-100mm
T4 Steel Plate: thickness 2-200mm x width 200-810mm
Surface Finish: Black, Rough Machined, Turned or as per given requirements.
2.Relevant Steel Specifications of AISI T4 High Speed Tool Steels
| Country | USA | German | Japan |
| Standard | ASTM A600 | DIN EN ISO 4957 | JIS G4403 |
| Grades | T4/T12004 | S 18-1-2-5/1.3255 | SKH3 |
3.AISI T4 Tool Steel and Equivalents’ Chemical Composition
| ASTM A600 | C | Mn | P | S | Si | Cr | V | W | Mo | Co | ||||||||
| T4 | 0.70 | 0.80 | 0.10 | 0.40 | 0.03 | 0.03 | 0.20 | 0.40 | 3.75 | 4.50 | 0.80 | 1.20 | 17.50 | 19.00 | 0.40 | 1.00 | 4.25 | 5.75 |
| DIN ISO 4957 | C | Mn | P | S | Si | Cr | V | W | Mo | Co | ||||||||
| S 18-1-2-5/1.3255 | 0.75 | 0.83 | … | 0.40 | 0.03 | 0.03 | … | 0.45 | 3.80 | 4.50 | 0.80 | 1.20 | 17.50 | 18.50 | 0.50 | 0.80 | 4.50 | 5.50 |
| JIS G4403 | C | Mn | P | S | Si | Cr | V | W | Mo | Co | ||||||||
| SKH3 | 0.73 | 0.83 | … | 0.40 | 0.03 | 0.03 | … | 0.45 | 3.80 | 4.50 | 0.80 | 1.20 | 17.00 | 19.00 | … | … | 4.50 | 5.50 |
4.High Speed Steel T4 Tool Steel Mechanical Properties
- Physical Properties of High Speed T4 Tool Steels
- Physical properties (average values) at ambient temperature
- Modulus of elasticity [103 x N/mm2]: 217
- Density [g/cm3]: 8.70
- Thermal conductivity [W/m.K]: 19.0
- Electric resistivity [Ohm mm2/m]: 0.65
- Specific heat capacity[J/g.K]: 0.46
- Mechanical Properties of T-4 Steel
| Properties | Metric | Imperial |
| Modulus of elasticity | 190-210 GPa | 27557-30458 ksi |
| Poisson’s ratio | 0.27-0.30 | 0.27-0.30 |
- Thermal Properties of T4 Tool Steels
| Properties | Metric | Imperial |
| Thermal expansion co-efficient | 11.9 µm/m°C | 6.6 µin/in°F |
Forging of T4 steel can be carried out from 850 to 1120°C (1775 to 2100°F).
- Preheat T4 steel material uniformly and slowly to 860-880°C.
- Increase the forging temperature up to 1050-1120°C.
- T4 hss tool steel should be cooled very slowly after forging.
6.AISI/ASTM T4 Tool Steel Heat Treatment and Properties
- Hardening
Harden T4 high speed tool steel from a temperature of 1260-1290oC followed by oil, air quenching or warm bath at 550oC. Hardness after quenching is 63-66 HRC.
- Annealing
T4 steel should be annealed after hot working. Increase the temperature of T4 high speed steel to 860°C(Max220°C per hour). Hold at the temperature and then cool slowly with the furnace. The annealed hardness achieved should be below HB255.
- Tempering
Tempering temperature: 2x 560-580oC. Hardness after tempering is 64-65 HRC.
7.Applications of ASTM/AISI T4 Tool Steel
AISI T4 high speed tool steels are widely used as cutting tools, broaches and cold extrusion punches, turning, planing and milling cutters for roughing work.
Typical applications are:
- Drills,
- Milling Cutters,
- Thread Cutting Tools,
- Knurling Tools,
- Cold extrusion punches
- Broaches etc.
Besides of ASTM/AISI T4 high speed tool steel materials, we are also capable of supplying T1 high speed steel, T10 tool steels, T15 tool steel etc. Just contact us for more details and latest price offer. If you have any questions, also leave a comment below.