Designation by Standards
Chemical Composition (in weight %)
1.2345 steel is a 5% chromium hot work tool steel designed particularly for applications requiring extreme toughness combined with good red hardness. It provides an extra margin of safest in tools subject to heavy hammer blows, and those tools containing deep recesses or sharp corners. While 1.2345 has been designed primarily as a hot work tool steel, it has been used in many cold work applications where extra toughness is required at the sacrifice of some wear resistance.
1.2345 has been used primarily for tools requiring resistance to softening at elevated temperatures. Such tools include forging dies and punches, die-casting dies, aluminum extrusion dies, hot heading dies, piercing and forming punches, etc.
Physical properties (avarage values) at ambient temperature
Modulus of elasticity [103 x N/mm2]: 215
Density [g/cm3]: 7.70
Thermal conductivity [W/m.K]: 25.0
Electric resistivity [Ohm mm2/m]: 0.52
Specific heat capacity[J/g.K]: 0.46
Coefficient of Linear Thermal Expansion 10-6 oC-1
Heat to 760-820oC, cool slowly in furnace. This will produce a maximum Brinell hardness of 250.
To relieve machining strains for greater accuracy in hardening, first rough machine, then anneal below the critical 649/677oC a minimum of one hour at temperature, and cool very slowly, followed by finish machining.
Harden from a temperature of 1000-1040oC followed by air, oil warm bath (450-550oC) quenching. Hardness after quenching is 54-58 HRC.
Tempering temperature: See the diagram bellow.
Tempering Temperature (oC) vs. Hardness (HRC) vs. Tensile Stregth (N/mm2)
Heat slowly and uniformly to a temperature of between 1093/1135oC and forge. Do not work the steel below 927oC. Reheat as often as necessary.
The machinability of 1.2345 may be rated between 55% and 65% of a 1% carbon water hardening tool steel, or about 40% to 50% of B1112.
To salvage tools and dies by welding, preheat to 538oC in a furnace and weld with uncoated arc equipment (atomic hydrogen or heliarc). Keep the temperature of the die above 316oC at all times by reheating until the welding is completed. Upon completion of the weld, return the work piece to the preheating furnace, equalize, and cool in the furnace. Welding should be performed in the annealed condition. However, if welding is performed in the hardened condition, the tool should be retempered at 538oC after hardening. The electrode material used in the weld rod should be of similar analysis to the base material.
All technical information is for reference only.