EN19/708M40 Alloy Steel-BS970

EN19/708M40 Alloy Steel manufacturers and suppliers,supplied with round rods,square/flat bars,rollers,shafts,blocks and forging pieces.

EN19/708M40 grade is a low-alloy steel including chromium and molybdenum as strengthening elements which has good strength and toughness, ductility,weldability and machinability. EN19/708M40  is widely used in the automotive, agricultural ,oil and gas industry. Typical uses are forged gears and shafts, spindles, fixtures, jigs and collars.

Chemical Composition
Grade C Si Mn Cr Mo P S
DIN 42CrMo4
0.38-0.45 ≤0.4 0.6-0.9 0.9-1.2 0.15-0.3 ≤0.025 ≤0.035
AISI/SAE 4140 0.38-0.43 0.15-0.35 0.7-1.0 0.8-1.1 0.15-0.25 ≤0.035 ≤0.04
JIS SCM440 0.38-0.43 0.15-0.35 0.6-0.85 0.9-1.2 0.15-0.3 ≤0.035 ≤0.04
GB 42CrMo  0.38-0.45  0.17-0.37  0.5-0.8  0.9-1.2  0.15-0.25  ≤0.035  ≤0.035
BS EN19 0.35-0.45 0.15-0.35 0.5-0.8 0.9-1.5 0.2-0.4 0.035 0.035
Shape Size(mm) Process Tolerance Length(mm)
Round Φ6-Φ50 Cold Drawn H11 3000-5800
Round Φ40-Φ300 Hot Rolled -0/+3mm 3000-10000
Round Φ120-Φ1000 Hot Forged -0/+3mm 3000-10000
Flat/Square/Block Thickness:120-800
Hot Forged -0/+3mm 500-6000

Heat Treatment
Normalizing For EN19/708M40 
1.Nominal normalizing temperature:840-880°C
2.Hold the temperature for several hours
3.Cooling in the air

Annealing For EN19/708M40 
1.Nominal Annealing temperature:790-840°C
2.Cool slowly in the furance
3.Maximum Brinell hardness of 225

Hardening and Tempering(QT) For EN19/708M40 
1.Nominal Hardening temperature:830-860°C
2.Hold at this temperature then quench in oil or water
3.Tempering  as soon as possible when the temperature low to ambient
4.Heat uniformly to the suitable temperature of 540-680°C
5.keep the material out of the furnace ,then cool in the air

Stress Relieve For EN19/708M40 
1.Nominal Stress Relieve temperature in the Quenched and Tempered condition:about 30-50°C below the tempering temperature.
2..Nominal Stress Relieve temperature in the Annealed condition:600-650°C
3.Cooling in the air.

Mechanical Property( for reference only)
1.Tensile strength: 850-1000MPa
2.Yield point: Min665MPa
3.Percentage reduction of area after fracture: 52%
4.Elongation after fracture: 13%
5.Impact test (+20°C): Transverse – 26~42J; Longitud – 49~55J

Delivery Condition
1.Shape:Round/Square / Flat/Shafts/Rollers/Blocks
2.Surface condition:Black surface/Bright surface
3.Heat Treatment:Normalized/Annealed/QT
4.Straightness:Max 3mm/m(Enhanced straightness may be available on request)
5.Length:3000-5800mm suitable for 20″container.  above 6000mm,suitable for 40″ container
6.Grain Size: 5-8 acc to ASTM E112-96
7.Ultrasonic Standard: Sep1921/ASTM A388/EN 10228-3
8.Typical Hardness:HB269-302
9.Non Metallic Inclusion: 2 max acc to ASTM E45 /K4≤20 acc to DIN 50602
10.Forging Ratio: minimum 4 : 1
11.Ingot Melting:EAF+LF+VD
12.Marking: Grade/Weight/Length/Size/Heat Number

Quality Certification
A material test report(Inspection Certificate EN 10204 3.1) will be provided, documenting the following:
1.Chemical analysis
2.Mechanical properties
3.Surface hardness
4.Non Metallic Inclusion
5.Heat Treatment Process
6.Grain size
7.Forging ratio
8.NDE test method/criteria