The content of 4140 steel includes chromium, molybdenum and iron. The molybdenum and chromium components give it a uniform hardness, as well as high strength. Because of this strength, 4140 steel is easily machined and responds well to heat treatment. 4140 steel is tough with high fatigue strength. The list of industries that use it to manufacture their products is extensive because of the versatility found in this grade of steel. It has a tensile strength of 95,000 psi and yield strength of 60,000 psi. 4140 steel is available for purchase in bar shapes, rods, sheets and strips in sizes suitable for a wide range of uses.
Chemical composition
Data |
4130 |
4140 |
4142 |
Carbon max. % |
0.28 – 0.33 |
0.38 – 0.43 |
0.40 – 0.45 |
Manganese % |
0.40 – 0.60 |
0.75 – 1.00 |
0.75 – 1.00 |
Phosphorous, max. % |
0.04 |
0.04 |
0.04 |
Sulfur, max. % |
0.04 |
0.04 |
0.04 |
Silicon, min.% |
0.15 – 0.35 |
0.15 – 0.35 |
0.15 – 0.35 |
Chrome, max. % |
0.80 – 1.10 |
0.80 – 1.10 |
0.80 – 1.10 |
Molybdenum, max. % |
0.15 – 0.25 |
0.15 – 0.25 |
0.15 – 0.25 |
Mechanical Properties
The minimum wall thickness at any point shall not be more than 12.5% under the nominal wall thickness specified.
Mechanicals |
Heat Condition |
Hardness |
Yield |
Tensile |
A519-4130 / 4140 |
Quenched and Tempered |
28-32 RC |
Not Tested |
Not Tested |
API 5CT L80 in 4519-4100 |
Quenched and Tempered |
18-22 RC |
80 – 95 ksi |
95 ksi min |
API 5CT P110 in 4519-4100 |
Quenched and Tempered |
30-36 RC |
110 – 140 ksi |
125 ksi min |
API 5CT Q125 in 4519-4100 |
Quenched and Tempered |
32-36 RC |
125 – 150 ksi |
135 ksi min |
Heat Conditions for 4100 Alloys
Condition |
Grade |
Medium |
Annealed |
A519-4130 CD |
Air |
Annealed or Normalized |
A519-4130 /A519-4140 |
Air |
Quenched and Tempered |
A519-4130 |
Water |
Quenched and Tempered |
A519-4140 |
Polymer or Oil |
Quenched and Tempered |
A519-4142 |
Oil |
Tolerances
Condition |
OD |
Wall |
Annealed or Normalized |
ASTM A519 |
ASTM A519 |
Quenched and Tempered |
+/-1% |
+/-12.5% |