AISI 4340 1.6511 36CrNiMo4 SNCM439 Forged Round Bar Annealing

Brand Name:Guangda
Certification:DNV, BV, Rina, ISO, GL, ABS, LR ,CCS ,PED
Delivery Time:15-45 work days
Payment Terms:L/C, D/A, D/P, T/T
Place of Origin:Jiangsu China
Supply Ability:500000 ton/year
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Address: Langanqiao Development Zone, Fenghuang Town, Zhangjiagang City, Jiangsu Province, 215614, P.R. China.
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AISI 4340 | 1.6511 | 36CrNiMo4 | SNCM439 Forged Round Bar Alloy Steel Bar


AISI 4340 steel is a medium carbon, low alloy steel known for its toughness and strength in relatively large sections. AISI 4340 is also one kind of nickel chromium molybdenum steels. 4340 alloy steel is generally supplied hardened and tempered in the tensile range of 930 – 1080 Mpa. Pre hardened and tempered 4340 steels can be further surface hardened by flame or induction hardening and by nitriding. The 4340 steel has good shock and impact resistance as well as wear and abrasion resistance in the hardened condition. AISI 4340 steel properties offer good ductility in the annealed condition, allowing it to be bent or formed. Fusion and resistance welding is also possible with our 4340 alloy steel. ASTM 4340 material is often utilized where other alloy steels do not have the hardenability to give the strength required. For highly stressed parts it is excellent choice. AISI 4340 alloy steel can also be machined by all customary methods.


AISI 4340 steel Manufacturer and Exporter,supplied with round,square,flat,block,and shaft etc.AISI 4340 is defined as a heat treatable and low alloy steel which has 0.8% Cr, 0.2% Mo and 1.8% Ni as strengthening alloy elements.Compared with AISI 4140,it has higher strength and toughness,also it has very good fatigue resistance, wear resistance and atmospheric corrosion resistance.AISI 4340 is generally supplied in hardened and tempered condition with the tensile range of 930 – 1080 Mpa ,hardness 280-320HB.Pre hardened and tempered 4340 can be further surface hardened by flame or induction hardening and by nitriding.


Forged Round Bar AISI 4340 Product features


MaterialAISI 4340 1.6511
TypeForged bar ,round ,square, flat, block, shaft etc.
Diameterφ150-1500mm
LengthMax 10000mm (10m)
SurfaceBlack, peeled, polishing, bright, sand blast, hair line, etc.
ApplicationHeavy machinery axle,turbine shaft blade, high load of transmission parts, fasteners, crank shafts, gears, as well as heavily loaded parts for motor construction etc.
Tensile strength testDIN EN ISO 6892-1
Impact testDIN EN ISO 148-1
UTDIN EN10228 Quality-Class 3 C/c or D/d
Grain sizeASTM E112 / EN ISO 643
Applicable standardEN10250,EN10083,SEW550 etc
CertificateEN 10204 / 3.1 3.2

Forged Round Bar Forged Round Bar AISI 4340 Chemical Compostion

StandardGradeCSiMnPSCrNiMo
ASTM A2943400.38-0.430.15-0.350.6-0.8≤ 0.035≤ 0.040.7-0.91.65-2.00.2-0.3

EN10250
36CrNiMo4
0.32-0.4

≤ 0.4

0.5-0.8

≤ 0.035

≤ 0.035

0.9-1.2

0.90-1.2

0.15-0.3
1.6511

BS 970
EN24
0.36-0.44

0.1-0.4

0.45-0.7

≤ 0.035

≤ 0.04

1.0-1.4

1.3-1.7

0.2-0.35
817M40
JIS G4103SNCM4390.36-0.430.15-0.350.6-0.9≤ 0.03≤ 0.030.6-1.01.6-2.00.15-0.3
GB 307740CrNiMoA0.37-0.440.17-0.370.5-0.8≤ 0.025≤ 0.0250.6-0.91.25-1.650.15-0.25

Forged Round Bar AISI 4340 Mechanical properties


Density g/cm37.85
Melting point °C1427
Poisson's ratio0.27-0.30
Machinability (AISI 1212 as 100% machinability)50%
Thermal expansion co-efficient µm/m°C12.5
Thermal conductivity W/(m.K)44.5
Modulus of elasticity 10^3 N/mm^2210
Electric resistivity Ohm.mm2 /m0.19
Specific heat capacity J/(kg.K)460

Modulus of elasticity 10^3 N/mm2
100 ℃200 ℃300 ℃400 ℃500 ℃
205195185175165

Thermal expansion 10^6 m/(m.K)
100 ℃200 ℃300 ℃400 ℃500 ℃
11.112.112.913.513.9

Mechanical ConditionTUVWXYZ
Ruling Section (mm)1501006330303030
Tensile Strength Mpa850-1000930-10801000-11501080-12301150-13001230-1380>1550
Yield Strength,Mpa≥665≥740≥835≥925≥1005≥1080≥1125
Elongation %≥13≥12≥12≥11≥10≥10≥5
Izod Impact J≥54≥47≥47≥41≥34≥24≥10
Charpy Impact J≥50≥42≥42≥35≥28≥20≥9
Brinell Hardness HB248-302269-331293-352311-375341-401363-429>444

Forged Round Bar AISI 4340 Forging


Forging temperature should be carried out between 1150℃-1200℃,The lower the forging-ending temperature ,the finer the grain size .hold suitable time for the steel to be thoroughly heated before forge, but don’t forge below minimum forging temperature 850°C. AISI 4340 has good forging characteristics,but crack is easily occured when improper cooling way after forged,so it should be cooled as slowly as possible in still air or in sand after forged.


Forged Round Bar AISI 4130 Application


AISI 4340 is often used in preference to AISI 4140 at the higher strength levels because of its better hardenability and improved CVN impact toughness.Typical applications include:Heavy-duty axles, shafts, heavy-duty gears,spindles, pins, studs, collets, bolts, couplings,sprockets, pinions, torsion bars, connecting rods,crow bars, conveyor parts,forged hydraulic,forged steel crankshafts etc.


AISI 4340 steel is used in most industry sectors for applications requiring higher tensile/yield strength than 4140 steel can provide.

Some typical applications such as:


  • Aircraft Landing Gear
  • Automotive,
  • Oil and Gas Drilling,
  • Forging,
  • Warm and Cold Forming,
  • Machine Building,
  • Transfer Systems, like power transmission gears and shafts.
  • General engineering industries and structural use applications, such as: heavy duty shafts, gears, axles, spindles, couplings, pins, chucks, molds etc.

About Guangda For forged round bar

  1. Directly manufactuer -- One stop for quality forged round bars
  2. Sold more than 100k tons for the round bars per year for overseas market.
  3. Register the exclusive trademark of GD in Europe.
  4. Experience for more than 10 years with quick delivery time and fast service.
  5. Listed company. Strong scientific research ability , Strength for Market experience and customer service .
  6. Certificate PED,DNV, BV, Rina, ISO, GL, ABS, LR etc.





AISI 4340 steel

4340 alloy steel

4340 round bar

China AISI 4340 1.6511 36CrNiMo4 SNCM439 Forged Round Bar Annealing supplier

AISI 4340 1.6511 36CrNiMo4 SNCM439 Forged Round Bar Annealing

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