AISI /SAE 4340 Steel is a Alloy Structural Steel belong to ASTM A29/A29M Steel Grade standard. AISI 4340 used in Oil and Gas industry and Large Machinery Strutural. 4340 Steel China Supplier and factory Otai Special Steel Supply 4340 steel in Round bar, Plate, Flat bar, Square, Forging Ring and others any shape. And provide cutting, sawing, milled, machining processing. Steel SAE 4340 PDF Down
1.Supply Form of 4340 Steel -ASTM A29/A29M Alloy Structural Steel
2.Supply Range of AISI 4340 Alloy Steel
AISI 4340 Steel Round Bar: diameter 5mm – 400mm
SAE 4340 Steel Plate: thickness 5 –500mm x width 200– 2300mm
ASTM 4340 Steel Block: 210mm x 500-810mm
3.Chemical Composition of AISI 4340 Alloy Steel Material
| ASTM A29/A29M | C | Si | Mn | P | S | Cr | Mo | Ni |
| 4340/G43400 | 0.38～0.43 | 0.15～0.35 | 0.60～0.80 | 0.025 Max | 0.025 Max | 0.70～0.90 | 0.20～0.30 | 1.65～2.00 |
| DIN 17220, EN 10083 | C | Si | Mn | P | S | Cr | Mo | Ni |
| 1.6511/36CrNiMo4 | 0.30～0.40 | ≤0.40 | 0.50～0.80 | 0.035 Max | 0.035 Max | 0.90～1.20 | 1.50～0.30 | 0.90～1.20 |
| GB/T 1229 | C | Si | Mn | P | S | Cr | Mo | Ni |
| 40CrNiMo | 0.37～0.44 | 0.17～0.37 | 0.50～0.80 | 0.030 Max | 0.030 Max | 0.60～0.90 | 0.15～0.25 | 1.25～1.65 |
| JIS G4105 | C | Si | Mn | P | S | Cr | Mo | Ni |
| SNCM439 | 0.36～0.43 | 0.15～0.35 | 0.60～0.90 | 0.030 Max | 0.030 Max | 0.60～1.00 | 0.15～0.30 | 1.60～2.00 |
4.4340 alloy Steel Equivalent and Related Speciation
| USA | German | Japan | China | ISO |
| ASTM 29/A29M | DIN 17350 | JIS G4404 | GB/T 1229 | ISO 683/18 |
| 4340 | 1.6511/36CrNiMo4 | SNCM439 | 40CrNiMo | 36CrNiMo4 |
5.ASTM AISI 4340 alloy Steel Material Mechanical Properties
Hardness, Rockwell C: 22 HRc, Density: 7.85kg/m3
Tensile strength: 655 MPa .
Melting point: 1416°C
Thermal expansion: 12.2 µm/m°C (20-100 ºC)
Elastic modulus: 190-210 GPa (at 25 ºC ).
6.Forged of AISI 4340 Oil and Gas industry Steel material metal
Forged AISI 4340 steel at 1150-1200 ºC. no forging when below 850 ºC.
7.Heat Treatment of SAE/AISI 4340 Alloy Steel
- Annealing
Slowly heat to 800～8500 ºC, keep enough time, ensure heat thoroughly. then cooling in furnace to 480 ºC, then cool in air. After annealing, the hardness 92 HBS Max.
- Hardening & Quenching
4340 Steel is usually used at 18-22 HRc, If needs, AISI 4340 alloy steel can be hardened or Quenching by cold work. Quenching medium: oil
- Tempering
/ ℃ tempering temperature: 205 ~ 649°C.
After tempering hardness HRC: 18-25 HRc.
8.Application of Sae AISI 4340 Steel
4340 alloy steel used for Structural products. As below:
Oil and gas sector, like collets, connection rods, conveyor pins, stem assemblies, gears, Bearings
9.Quality Assured of Sae AISI 4340 Alloy Steel
Quality assured by Our ISO 9001:2008 quality management system. Our all 4340 steel all had by SEP 1921-84 ultrasonic inspection (UT Test). Quality Grade: E/e, D/d, C/c.
If you have any 4340 Alloy steel inquiry and question for Price, Application, hot treatment, please don’t hesitate contact us.
