AISI 4145
LOW ALLOY STEEL
LOW ALLOY 4145: ASTM A29
GENERAL SCOPE
AISI 4145 low alloy steel containing 0.20% molybdenum is widely used particularly throughout oil patch applications. Similar to 4140 which has a lower carbon level it has improved hardenability and is more commonly used at higher strength levels.
Larger diameters are often supplied with higher molybdenum level, 0.35% max, this may also be used on higher strength variants at smaller diameters. This grade is used extensively for drill collars.
The hardenability limitations of this grade (depth to which it will harden / obtain the specified mechanical properties after heat treatment) must always be taken into account when designing and selecting equipment.
CHEMICAL COMPOSITION
| C | Si | Mn | P | S | Cr | Mo | Fe | |
|---|---|---|---|---|---|---|---|---|
| Min | 0.43 | 0.15 | 0.75 | . | . | 0.80 | 0.15 | 0.00 |
| Max | 0.48 | 0.35 | 1.00 | 0.035 | 0.040 | 1.10 | 0.25 | 0.00 |
MECHANICAL PROPERTIES
Condition: Hardened and Tempered to 22 HRC max
| U.T.S | 100 KSI Min | (689 N/mm2) |
| 0.2% Proof Stress | 80 KSI Min | (551 N/mm2) |
| Elongation | 20 % | |
| Red of Area | 40 % | |
| Condition: Hardened and Tempered to 30-36 HRC max |