AISI 4130 pipe
4130 seamless pipe (ASTM A519 Grade 4130)
Seamless chromoly pipe for high-pressure lines, made to ASTM A519 Grade 4130 and heat treated to the strength and hardness your line needs.
4130 seamless pipe is chromium-molybdenum alloy steel pipe, usually ordered to ASTM A519 Grade 4130 and heat treated to a set strength and hardness. We supply it from NPS 1 to 8 in Sch 80, Sch 160 and XXS, and as heavy-wall sizes ordered by outside and inside diameter such as 5.5 in OD by 3 in ID, normalized or quenched and tempered, for choke and kill, cement, mud, well test and flowback lines from 7,500 to 15,000 psi.
What ASTM A519 covers, and what the order must add
ASTM A519 is the US specification for seamless carbon and alloy steel mechanical tubing up to 12-3/4 in (323.8 mm) outside diameter. It sets the chemistry of Grade 4130, the dimensions and tolerances, and the heat treatment conditions: annealed, normalized, quenched and tempered, and stress relieved. It does not set tensile or hardness requirements unless the buyer orders its supplementary requirements, and it does not address pressure service.
So when 4130 pipe goes into a pressure line, the purchase order carries what A519 leaves out. A complete order states:
| Item | Example |
|---|---|
| Specification and grade | ASTM A519 Grade 4130 (UNS G41300) |
| Size and wall | NPS and schedule, or OD by ID: 3.5 in OD by 2.3 in ID |
| Heat treatment | Quenched and tempered |
| Strength | 75 ksi (517 MPa) min yield, 95 ksi (655 MPa) min tensile, the API 6A 75K level |
| Ductility | 17% min elongation, 35% min reduction of area |
| Hardness | 22 HRC max for sour service, or a range |
| Toughness | Charpy V-notch at -20 °F (-29 °C), the low end of API 6A temperature class P |
| Nondestructive examination | Ultrasonic, full length, to the standard you name |
| Certificate | EN 10204 3.1, or 3.2 with your inspector |
The strength callouts are explained in 4130 75K, 80K and L80.
Sizes and wall thickness
Pipe ordered by nominal size follows the outside diameters and schedule walls of ASME B36.10M. Wall and bore are in inches; weight is plain end.
| NPS | OD, in (mm) | Sch 80 | Sch 160 | XXS | XXS weight, lb/ft |
|---|---|---|---|---|---|
| 1 | 1.315 (33.4) | 0.179 / 0.957 | 0.250 / 0.815 | 0.358 / 0.599 | 3.66 |
| 1-1/2 | 1.900 (48.3) | 0.200 / 1.500 | 0.281 / 1.338 | 0.400 / 1.100 | 6.41 |
| 2 | 2.375 (60.3) | 0.218 / 1.939 | 0.344 / 1.687 | 0.436 / 1.503 | 9.04 |
| 2-1/2 | 2.875 (73.0) | 0.276 / 2.323 | 0.375 / 2.125 | 0.552 / 1.771 | 13.71 |
| 3 | 3.500 (88.9) | 0.300 / 2.900 | 0.438 / 2.624 | 0.600 / 2.300 | 18.60 |
| 4 | 4.500 (114.3) | 0.337 / 3.826 | 0.531 / 3.438 | 0.674 / 3.152 | 27.57 |
| 5 | 5.563 (141.3) | 0.375 / 4.813 | 0.625 / 4.313 | 0.750 / 4.063 | 38.59 |
| 6 | 6.625 (168.3) | 0.432 / 5.761 | 0.719 / 5.187 | 0.864 / 4.897 | 53.21 |
| 8 | 8.625 (219.1) | 0.500 / 7.625 | 0.906 / 6.813 | 0.875 / 6.875 | 72.49 |
Wall / ID in inches. Weights by the ASME B36.10M formula, 10.69 x (OD - wall) x wall.
Heavy-wall lines are often ordered by outside and inside diameter instead. These are the OD by ID sizes we supply most often; other combinations can be quoted to your drawing.
| OD x ID, in | Wall, in (mm) | Weight, lb/ft | Note |
|---|---|---|---|
| 3.5 x 2.3 | 0.60 (15.2) | 18.60 | 3 in XXS |
| 4 x 2.5 | 0.75 (19.0) | 26.06 | - |
| 4.5 x 3 | 0.75 (19.0) | 30.07 | Heavier than 4 in XXS |
| 5 x 3 | 1.00 (25.4) | 42.76 | - |
| 5.5 x 3 | 1.25 (31.8) | 56.79 | Common for 15,000 psi lines |
Chemical composition
| C | Mn | P max | S max | Si | Cr | Mo |
|---|---|---|---|---|---|---|
| 0.28 to 0.33 | 0.40 to 0.60 | 0.040 | 0.040 | 0.15 to 0.35 | 0.80 to 1.10 | 0.15 to 0.25 |
Oilfield specifications often tighten phosphorus and sulfur and cap nickel below 1% for sour service. We quote to the limits on your order.
More on the steel itself, its equivalents and properties, is in AISI 4130 steel.
Heat treatment and strength levels
The same 4130 pipe can be anything from a soft normalized tube to a high-strength line, depending on the heat treatment. These are the levels buyers order most:
| Condition | Strength | Typical use |
|---|---|---|
| Normalized | Typical yield about 64 ksi (440 MPa), tensile about 97 ksi (670 MPa); typical values, not minimums | Machining stock and lines that do not need quench and temper strength |
| Quenched and tempered, API 6A 75K | 75 ksi (517 MPa) min yield, 95 ksi (655 MPa) min tensile, 17% elongation, 35% reduction of area | The common level for pressure equipment |
| Quenched and tempered, L80 type | 80 to 95 ksi (552 to 655 MPa) yield, 95 ksi min tensile, 23 HRC max, the API 5CT L80 limits | Lines bought to a controlled-yield callout |
| Quenched and tempered for 15,000 psi | 85 ksi (586 MPa) min yield, 110 ksi (758 MPa) min tensile | Our standard level for 15,000 psi lines |
How the temperatures and times give these results is covered in 4130 heat treatment.
Sour service
For lines that carry hydrogen sulfide, NACE MR0175 / ISO 15156-2 accepts low-alloy steels such as 4130 at 22 HRC maximum, with less than 1% nickel, in the normalized or quenched and tempered condition. Order sour-service pipe with that hardness limit and a hardness survey on the certificate. The full set of rules, including welds, is in 4130 for sour service.
Where 4130 pipe is used
- Choke and kill manifolds and rigid choke and kill lines, see choke and kill lines
- Mud and cement manifolds, and high-pressure mud and cement lines
- Mud gas separators and debris or junk catcher manifolds
- Well test, flowback and underbalanced drilling packages
- BOP accumulator unit piping
Ordering the fittings and long sweeps with the pipe keeps strength and hardness consistent across every weld in the line.
Ordering
Write each line with size, wall, heat treatment, strength, hardness and tests, for example:
Seamless pipe, ASTM A519 Grade 4130, 5.5 in OD x 3 in ID, quenched and tempered, 85 ksi min yield, 110 ksi min tensile, Charpy at -20 °F, UT full length, EN 10204 3.1, 120 ft
Seamless pipe, ASTM A519 Grade 4130, 3 in XXS, quenched and tempered, 75 ksi min yield, 95 ksi min tensile, 22 HRC max with hardness survey, NACE MR0175 / ISO 15156-2, EN 10204 3.1, 80 ft
Frequently asked questions
Is ASTM A519 4130 pipe suitable for pressure service?
ASTM A519 is a mechanical tubing specification: it fixes the chemistry and dimensions but sets no pressure rating and, unless ordered, no tensile or hardness requirements. 4130 pipe is used for pressure lines when the order adds the heat treatment, strength, hardness, impact and NDE requirements and the line is rated to the designer's code. That is how we quote it.
What is the difference between 4130 pipe and 4130 tubing?
The steel is the same. Pipe is usually ordered by nominal pipe size and schedule to ASME B36.10M, for example 3 in XXS. Tubing is usually ordered by outside diameter and wall or inside diameter, for example 5.5 in OD by 3 in ID. We supply both.
Can you supply the matching fittings?
Yes. Elbows, tees, reducers, long sweep and integral fittings can be ordered with the pipe, heat treated to the same strength level and hardness, so the line arrives with one set of certificates.
Do you hold 4130 pipe in stock in the US?
No. Every order is cut, heat treated and tested to your line list and ships from our works in Gujarat, India. See how a US order works.