SAE 4140 Steel Bar

WALDUN is one of the best SAE4140 Steel bar manufacturers and suppliers in China, can supplied with round rods,square/flat bars,rollers,shafts,blocks and forging pieces.

SAE4140 grade is a low-alloy steel including chromium and molybdenum as strengthening elements which has good strength and toughness, ductility,weldability and machinability. SAE4140 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 per ASTM A29

GRADE	C	Si	Mn	P	S	Cr	Mo
4140	0.38-0.43	0.15-0.35	0.75-1.00	≤ 0.035	≤ 0.040	0.80-1.10	0.15-0.25

SAE4140 Steel bar Size&Tolerance&Process

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 Width:120-1500	Hot Forged	-0/+3mm	500-6000

SAE4140 Steel Bar Heat Treatment

Normalizing For SAE4140
1.Nominal normalizing temperature:840-880°C
2.Hold the temperature for several hours
3.Cooling in the air

Annealing For SAE4140
1.Nominal Annealing temperature:790-840°C
2.Cool slowly in the furance
3.Maximum Brinell hardness of 225

Hardening and Tempering(QT) For SAE4140
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 SAE4140
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

SAE4140 Steel Bar 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