Prehardened steel|Other prehardened steel|42CrMo4QT
Hardox

42CrMo4QT / 1.7225QT

The steel 42CrMo4QT / 1.7225 is an all-purpose material, especially for use in mechanical engineering. Its high strength combined with high toughness makes it possible to use it in heavy-duty machine parts, e.g. axles, transmission shafts, gear wheels, etc.

This steel is also used in mechanical engineering, in tempered condition, which is additionally surface-hardened. It is a steel that is difficult to weld, so follow the instructions of the material manufacturer when using it.

Quenched and tempered

Chromium, Molybdenum steel for applications requiring high tensile strength and toughness values, in particular in medium and large cross sections in the quenched and tempered condition. The Molybdenum additions prevent the steel from being susceptible to temper brittleness.

Applications

4140 is the most commonly used of the high tensile steels with a wide range applications in automotive, Gear and Engine construction, Crankshafts, Steering knuckles, Connecting rods, Spindles, Intermediate gears, Pump and Gear shafts.

Mechanical Properties

Thickness 15 to 60 mm according to EN-10083-3

Thickness (mm) 8 < t < 20 20 < t < 60
Yield Strength Rp0,2 [N/mm2] min. 750 min. 650
Tensile Strength Rm [N/mm2] 1.000 - 1.200 900 - 1.100
Elongation A5 [%] min. 11 min. 12
Elongation Z [%] min. 45 min. 50
Impact Toughness ISO-V [J] min. 35 min. 35

Tensile testing and toughness according EN-10083-3

 

Thickness 80 to 110 mm

Thickness (mm) 80 ≤ t ≤110
Tensile Strength Rm [N/mm2] 950 - 1.100

Tensile test according to EN-10083-3 : Rm 950 -1100 MPa; Tensile test T/2 Rm≥ 900 MPa The other mechanical properties are just for information

Tolerances

Class C/N according to EN-10029

Nominal thickness Tolerances on nominal thickness 1)
Class A Class B Class C Class D
Lower Upper Lower Upper Lower Upper Lower Upper
> 3 < 5 -0.4 +0.8 -0.3 +0.9 -0 +1.2 -0.6 +0.6
> 5 < 8 -0.4 +1.1 -0.3 +1.2 -0 +1.5 -0.75 +0.75
> 8 < 15 -0.5 +1.2 -0.3 +1.4 -0 +1.7 -0.85 +0.85
> 15 < 25 -0.6 +1.3 -0.3 +1.6 -0 +1.9 -0.95 +0.95
> 25 < 40 -0.8 +1.4 -0.3 +1.9 -0 +2.2 -1.1 +1.1
> 40 < 80 -1.0 +1.8 -0.3 +2.5 -0 +2.8 -1.4 +1.4
> 80 < 150 -1.0 +1.8 -0.3 +2.5 -0 +2.8 -1.4 +1.4
> 150 < 250 -1.2 +2.4 -0.3 +3.3 -0 +3.6 -1.8 +1.8

 

Normal flatness tolerances Class N

Nominal thickness Steel type L Steel type H
Measuring length
1.000 2.000 1.000 2.000
> 3 < 5 9 14 12 17
> 5 < 8 8 12 11 15
> 8 < 15 7 11 10 14
> 15 < 25 7 10 10 13
> 25 < 40 6 9 9 12
> 40 < 250 5 8 8 11
Chemical Composition
Steel C Si Mn Cr Mo P S
42CrMo4 0,38%
0,45%		 <0,40% 0,60%
0,90%		 0,90%
1,20%		 0,15%
0,30%		 <0,025% <0,035%
Delivery Conditions

Plate Surface according to EN 10163-2

Cerificate 3.1 according to EN-10204