EN 10083-1:1991 3C40 Steel: Specifications & Listings
EN 10083-1:1991 3C40: A medium carbon special steel for quenching and tempering to EN 10083-1:1991 (printed 3 C 40), with controlled sulphur of 0.020 to 0.040% for better machinability. Supplied as semi-finished products, bars, rod, wide flats, hot rolled strip, sheet and plate, and forgings. Quenched and tempered tensile strength 650 to 800 MPa for ruling sections up to 16 mm.
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Chemical Composition (%)
C
Cr
Cr+Mo+Ni
Mn
Mo
Ni
P
S
Si
0.37-0.44
<=0.40
<=0.63
0.50-0.80
<=0.10
<=0.40
<=0.035
0.020-0.040
<=0.40
Mechanical Properties
Condition
Quenched and tempered, ruling section d <= 16 mm
Elongation
16% min
Tensile Strength
650 to 800 MPa
Yield Strength
460 MPa min
More data from EN 10083-1:1991
From the standard
Other composition limitsTable III and its notes
Designation as printed
3 C 40
Pair grade
2C40 has the same limits except sulphur, max. 0.035
Availability
Printed in brackets: introduced partly for the first time in this standard and not available from stock in all countries (Table III, note 6)
Improved machinability
Steels with lead or higher sulphur, up to about 0.100% S, may be supplied on request (Table III, note 3)
Restricted options
Without hardenability or quenched and tempered or normalized property requirements, a carbon range of 0.05 and/or Cr + Mo + Ni below 0.45 may be agreed (Table III, note 5)
Elements not quoted in Table III are not intentionally added without the purchaser's agreement, other than for finishing the heat. With hardenability requirements, slight deviations within Table IV are permitted except for carbon, phosphorus and sulphur.
Source: EN 10083-1:1991 (UNI EN 10083-1), Table III and its notes
Mechanical properties, quenched and tempered3 sections
Ruling section
Yield strength Re, min (MPa)
Tensile strength Rm (MPa)
Elongation A, min (%)
Reduction of area Z, min (%)
Impact KV, min (J)
d <= 16 mm, t <= 8 mm
460
650 to 800
16
35
30
16 mm < d <= 40 mm, 8 mm < t <= 20 mm
400
630 to 780
18
40
30
40 mm < d <= 100 mm, 20 mm < t <= 60 mm
350
600 to 750
19
45
30
Re is the upper yield strength or, if no yield phenomenon occurs, the 0.2% proof strength; A on gauge length 5.65 times the root of the original cross section; KV on longitudinal ISO V-notch test pieces, average of 3 values, no single value below 70% of the minimum. Ruling sections as in Appendix B. Sizes not listed are not covered by the standard.
Source: EN 10083-1:1991 (UNI EN 10083-1), Table IX
Mechanical properties, normalized3 sizes
Size
Yield strength Re, min (MPa)
Tensile strength Rm, min (MPa)
Elongation A, min (%)
d <= 16 mm, t <= 16 mm
320
580
16
16 mm < d <= 100 mm, 16 mm < t <= 100 mm
290
550
17
100 mm < d <= 250 mm, 100 mm < t <= 250 mm
260
530
17
Values also apply to the grades with hardenability requirements (H, HH, HL). Sizes not listed are not covered by the standard.
Source: EN 10083-1:1991 (UNI EN 10083-1), Table X
Maximum hardness by delivery conditionTable VIII
Shearability
Shearable in the untreated condition under suitable conditions (clause 5.3.2.3)
Values also apply to the grades with hardenability requirements (H, HH, HL); not applicable to continuously cast slabs not further deformed.
Source: EN 10083-1:1991 (UNI EN 10083-1), Table VIII
Hardenability, end quench test (H)Hardness band
Hardness band (HRC, minimum to maximum) by distance from the quenched end (mm)
1
2
3
4
5
6
7
8
9
10
11
13
15
20
25
30
Distance from quenched end (mm)
1
2
3
4
5
6
7
8
9
10
11
13
15
20
25
30
Maximum, HRC
60
60
59
57
53
47
39
34
31
30
29
28
27
26
25
24
Minimum, HRC
51
46
35
27
25
24
23
22
21
20
Applies when ordered as 3C40 H. Provisional values for non alloy steels; a manufacturer whose band falls outside these limits informs the purchaser at ordering (Table V, note 1). End quench test at 870 ± 5 deg C (Table XIII).
Source: EN 10083-1:1991 (UNI EN 10083-1), Table V
Restricted hardenability (HH, HL), provisionalTable VI
Symbol
1 mm (HRC)
4 mm (HRC)
HH4
-
38 to 57
HH14
54 to 60
38 to 57
HL4
-
27 to 46
HL14
51 to 57
27 to 46
Apply to both the 2C and 3C grade. The figure after the symbol gives the distances (mm) at which the limits apply.
Source: EN 10083-1:1991 (UNI EN 10083-1), Table VI
Heat treatmentTable XIII
Quenching
830 to 870 deg C
Quenching agent
Water or oil
Tempering
550 to 660 deg C
End quench test
870 ± 5 deg C
Normalizing
850 to 890 deg C
Guidance values except the end quench test temperature, which is binding. Lower quenching temperatures generally for water, upper for oil; austenitizing at least 30 min, tempering at least 60 min (guide values).
Source: EN 10083-1:1991 (UNI EN 10083-1), Table XIII
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