AISI 4140 Seamless Pipe is tubing made to the pipe schedule. Alloy pipe in the power industry generally refers to A335 material, but in the oil and gas market, 4140 Pipe is used. This product is made to the pipe schedule but uses A519-4140 as the controlling Seamless specification. The material is then heat treated to L80, P110 or the customer’s specified properties. This material is easily welded and is generally used for above ground applications and utilizes the fittings, flanges and other piping components with the same 4140 chemistry. This product is a good alternative to replace X65 through X80 piping items where the usage or repair is too small for mill production.
AISI 4140 is a low alloy steel containing molybdenum and chromium as strengthening agents. We stocks all AISI 4140 Pipes, 4140 Tubing, 4140 Flanges, 4140 Pipes Fittings, 4140 Elbow etc. The carbon content is nominally 0.30% and with this relatively low carbon content the alloy is excellent from the fusion weldability standpoint. The alloy can be hardened by heat treatment. Typical applications for 4140 low alloy steel include structural use such as aircraft engine mounts and welded tubing applications.
Alloy steels are designated by AISI four-digit numbers. They are more responsive to mechanical and heat treatments than carbon steels. They comprise different types of steels with compositions which exceed the limitations of B, C, Mn, Mo, Ni, Si, Cr, and Va in the carbon steels.
| Size Range | 2″ – 12” |
| Schedules | 20, 30, 40, Standard (STD), Extra Heavy (XH), 80, 100, 120, 140, 160, XXH & heavier |
| Standard | ASTM A519 |
| Grade | AISI 4140, L80, L110 |
Chemical composition % of A519 4140 Alloy Steel Seamless Pipe
| Element | Content (%) |
|---|---|
| Iron, Fe | 96.785 - 97.77 |
| Chromium, Cr | 0.80 - 1.10 |
| Manganese, Mn | 0.75 - 1.0 |
| Carbon, C | 0.380 - 0.430 |
| Silicon, Si | 0.15 - 0.30 |
| Molybdenum, Mo | 0.15 - 0.25 |
| Sulfur, S | 0.040 |
| Phosphorous, P | 0.035 |
The following table shows the physical properties of AISI 4140 alloy steel.
| Properties | Metric | Imperial |
|---|---|---|
| Density | 7.85 g/cm3 | 0.284 lb/in³ |
| Melting point | 1416°C | 2580°F |
The mechanical properties of AISI 4140 alloy steel are outlined in the following table.
| Properties | Metric | Imperial |
|---|---|---|
| Tensile strength | 655 MPa | 95000 psi |
| Yield strength | 415 MPa | 60200 psi |
| Bulk modulus (typical for steel) | 140 GPa | 20300 ksi |
| Shear modulus (typical for steel) | 80 GPa | 11600 ksi |
| Elastic modulus | 190-210 GPa | 27557-30458 ksi |
| Poisson's ratio | 0.27-0.30 | 0.27-0.30 |
| Elongation at break (in 50 mm) | 25.70% | 25.70% |
| Hardness, Brinell | 197 | 197 |
| Hardness, Knoop (converted from Brinell hardness) | 219 | 219 |
| Hardness, Rockwell B (converted from Brinell hardness) | 92 | 92 |
| Hardness, Rockwell C (converted from Brinell hardness. Value below normal HRC range, for comparison purposes only) | 13 | 13 |
| Hardness, Vickers (converted from Brinell hardness) | 207 | 207 |
| Machinability (based on AISI 1212 as 100 machinability) | 65 | 65 |
The thermal properties of AISI 4140 alloy steel are given in the following table.
| Properties | Metric | Imperial |
|---|---|---|
| Thermal expansion co-efficient (@ 0-100°C/32-212°F) | 12.2 µm/m°C | 6.78 µin/in°F |
| Thermal conductivity (@ 100°C) | 42.6 W/mK | 296 BTU in/hr.ft².°F |
The following table shows the physical properties of AISI 4140 Alloy Steel Seamless Pipes.
| Tensile Properties | ||||||||
| Grade Designation | Condition | Ultimate Strength | Yield Strength | Elongation in 2 in.or 50mm,% | Rockwell,Hardness B Scale | |||
| ksi | Mpa | ksi | Mpa | |||||
| 4140 | HR | 90 | 621 | 70 | 483 | 20 | 89 | |
| SR | 105 | 724 | 85 | 586 | 10 | 95 | ||
| A | 75 | 517 | 55 | 379 | 30 | 81 | ||
| N | 90 | 621 | 60 | 414 | 20 | 89 | ||
| Standard | Alloy Steel |
|---|---|
| AISI 4140 Alloy Steel | UNS G41400 |
| AISI 4340 Alloy Steel | UNS G43400 |
| AISI 4140 Alloy Steel | UNS G41400 |
| AISI 8620 Alloy Steel | UNS G86200 |
| GB/T 3077 | JIS | AISI/SAE | DIN | BS | ISO |
|---|---|---|---|---|---|
| 20Mn2-50Mn2 | SMn420-SMn443 | 1320-1345 | 20Mn5-50Mn7 | 150M19-160M36 | 22Mn6-42Mn6 |
| 15Cr-50Cr | SCr415-445 | 5115-5150 | - | 527A17 | 20Cr4-41Cr4 |
| 15CrMo | SCM415 | - | 15CrMo5 | 1653 | - |
| 35CrMo | SCM435 | 4137 | 34CrMo1 | - | - |
| 30CrMo | SCM420 | 4140 | 25CrMo4 | 25CrMo4 | |
| 30CrMoA | SCM430 | 4140 | 34CrMo4 | 34CrMo4 | |
| 42CrMo | SCM440 | 4140 | 42CrMo4 | 708M40 | |
| - | - | F11-91 | - | - | - |
| 38CrMoAl | SACM645 | - | - | - | 41CrAlMo74 |
| 50CrV | - | 6150 | 51CrV4 | - | - |
| 15-20CrMn | SMnC420 | 5115-5120 | 16MnCr5 | 16MnCr5 | |
| GCr15 | - | SAE52100 | 100Cr6 | - | - |
| GCr15SiMn | - | - | 100CrMnSi6-4 | - | - |
| 20CrMnMo(H) | SCM421(H) | 4119 | - | - | - |
| 40CrMnMo | SCM440 | 4142 | 42CrMo4 | 708A42 | 42CrMo4 |
| 20-50CrNi | SNC436 | 3115-3150 | 40NiCr6 | 640M40 | - |
| 12CrNi2 | SNC415 | 3415 | 14NiCr10 | - | - |
| 20CrNiMo | SNCM220 | 8620 | 21NiCrMo2 | 805M20 | 20NiCrMo2 |
| 34CrNiMo | - | - | 34CrNiMo6 | - | - |
| 34CrNi1Mo | - | - | 34CrNi1Mo6 | - | - |
| 40CrNiMo | SNCM439 | 4340 | 36CrNiMo4 | 816M40 | - |
Oil machinery steel series: AISI4150M, AISI4140, AISI 4140 etc.
Machinability A519 4140 Alloy Steel Seamless Pipe and Tubes
AISI 4140 alloy steel has good machinability in the annealed condition.
Forming A519 4140 Alloy Steel Seamless Pipe and Tubes
AISI 4140 alloy steel has high ductility. It can be formed using conventional techniques in the annealed condition. It requires more pressure or force for forming because it is tougher than plain carbon steels.
Welding A519 4140 Alloy Steel Seamless Pipe and Tubes
AISI 4140 alloy steel can be welded using all conventional techniques. However, the mechanical properties of this steel will be affected if it is welded in the heat treated condition, and post weld heat treatment should be performed.
Heat Treatment A519 4140 Alloy Steel Seamless Pipe and Tubes
AISI 4140 alloy steel is heated at 845°C (1550°F) followed by quenching in oil. Before hardening, it can be normalized by heating at 913°C (1675°F) for a long period of time followed by air cooling.
Forging A519 4140 Alloy Steel Seamless Pipe and Tubes
AISI 4140 alloy steel is forged at 926 to 1205°C (1700 to 2200°F)
Hot Working A519 4140 Alloy Steel Seamless Pipe and Tubes
AISI 4140 alloy steel can be hot worked at 816 to 1038°C (1500 to 1900°F)
Cold Working A519 4140 Alloy Steel Seamless Pipe and Tubes
AISI 4140 alloy steel can be cold worked using conventional methods in the annealed condition.
Annealing A519 4140 Alloy Steel Seamless Pipe and Tubes
AISI 4140 alloy steel is annealed at 872°C (1600°F) followed by slowly cooling in the furnace.
Tempering A519 4140 Alloy Steel Seamless Pipe and Tubes
AISI 4140 alloy steel can be tempered at 205 to 649°C (400 to 1200°F) depending upon the desired hardness level. The hardness of the steel can be increased if it has lower tempering temperature. For example, tensile strength of 225 ksi cab be achieved by tempering at 316°C (600°F), and a tensile strength of 130 ksi can be achieved by tempering at 538°C (1000°F).
Hardening A519 4140 Alloy Steel Seamless Pipe and Tubes
AISI 4140 alloy steel can be hardened by cold working, or heating and quenching.
AISI 4140 L80 Alloy Steel Seamless Pipes
| C | Mn | Mo | Cr | Ni | Cu | Ti | P | S | Si | V | Al | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | 0.380 | 0.750 | 0.150 | 0.800 | - | - | - | - | - | 0.150 | - | - |
| Max | 0.430 | 1.100 | 0.250 | 1.100 | - | - | - | 0.035 | 0.040 | 0.300 | - | - |
| Tensile Strength | 689 MPa min | 100,000 psi min |
| Yield Strength | 552 MPa min | 655 MPa max |
| 80,000 psi min | 95,000 psi max | |
| Total Elongation Under Load | 20.000 % | - |
| Hardness | 23 Max HRC |
| Tensile Strength | 862 MPa min | 125,000 psi min |
| Yield Strength | 758 MPa min | 965 MPa max |
| 110,000 psi min | 140,000 psi max | |
| Total Elongation Under Load | 13.000 % | - |
| Hardness | 30 Max HRC | - |
A519 4140 Alloy Steel Seamless Pipe and Tubes is sleeved into plastic bag individually, pieces wrapped with water-proof material, bundled with nylon rope. Clear labels are tagged on the outside of the package for easy identification of the quantity and product I.D. Great care is taken during operation and transportation.
A519 4140 Alloy Steel Seamless Pipe and Tubes packing will be according to international standard in bundles strapped by strips then into containers to avoid any damage

