AISI 4140 steel pipe is a low alloy steel that contains additions of chromium, molybdenum, and manganese in their alloy. In comparison to Grade 4130, the content of carbon in 4140 is slightly higher. This versatile alloy makes for an AISI 4140 Pipe with good properties. For instance, they have good resistance to atmospheric corrosion along with reasonable strength.
| Grade | C | Si | Mn | P | S | Cr | Ni | Mo | V |
| 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 | – |
