AISI 4140 ning kimyoviy tarkibi barqaror xususiyatlarni ta'minlash uchun standartlashtirilgan. Quyida standart diapazonlarni ekvivalent baholar bilan taqqoslaydigan jadval mavjud:
| Element | AISI 4140 (%) | EN 1.7225 (42CrMo4) (%) | JIS SCM440 (%) |
|---|---|---|---|
| Uglerod (C) | 0.38–0.43 | 0.38–0.45 | 0.38–0.43 |
| Marganets (Mn) | 0.75–1.00 | 0.60–0.90 | 0.60–0.85 |
| Kremniy (Si) | 0.15–0.30 | 0.15–0.40 | 0.15–0.35 |
| Xrom (Cr) | 0.80–1.10 | 0.90–1.20 | 0.90–1.20 |
| Molibden (Mo) | 0.15–0.25 | 0.15–0.30 | 0.15–0.30 |
| Fosfor (P) | 0,035 dan kam yoki unga teng | 0,035 dan kam yoki unga teng | 0,030 dan kam yoki unga teng |
| Oltingugurt (S) | 0,040 dan kam yoki unga teng | 0,035 dan kam yoki unga teng | 0,030 dan kam yoki unga teng |
| Temir (Fe) | Balans | Balans | Balans |
Ushbu kompozitsiya yuqori qattiqlashuv, mustahkamlik va charchoqqa chidamliligini ta'minlaydi, xrom korroziyaga chidamliligini oshiradi va molibden yuqori{0}}haroratga chidamliligini oshiradi.