Estimate a preliminary stress-relieving temperature range for common steels based on material grade, component type and required stress reduction.
Stress relieving is generally performed below the temperature at which the intended service microstructure would be substantially changed. The exact temperature must therefore be selected for the particular grade and prior heat-treatment condition.
| Steel | Equivalent | Indicative Stress-Relief Range | Typical Use |
|---|---|---|---|
| AISI 1018 | Low-carbon steel | 500–650 °C | Machined and fabricated components |
| AISI 1045 | C45 / EN8 | 500–650 °C | Machined shafts and components |
| AISI 4130 | 25CrMo4 | 500–650 °C | Fabricated and machined alloy-steel parts |
| AISI 4140 | 42CrMo4 / EN19 | 500–650 °C | Quenched-and-tempered machine components |
| AISI 4340 | 34CrNiMo6 / EN24 | 500–650 °C | High-strength components |
| AISI 5160 | 50CrV4 | 500–650 °C | Spring and fabricated components |
| AISI 52100 | 100Cr6 / EN31 | 150–250 °C | Bearing components |
| AISI A2 | 1.2363 | 500–650 °C | Cold-work tooling |
| AISI D2 | 1.2379 / SKD11 | 500–650 °C | Dies and wear-resistant tooling |
| AISI H13 | 1.2344 / SKD61 | 500–650 °C | Hot-work tooling |
Residual stresses can be introduced by welding, machining, forming, casting, grinding, rapid cooling and other manufacturing processes. These stresses can contribute to distortion when material is subsequently machined or exposed to service conditions.
Stress relieving uses controlled heating and cooling to reduce a portion of those internal stresses while attempting to preserve the desired material condition.
A stress-relieving temperature suitable for ordinary carbon steel may be unsuitable for a hardened tool steel, bearing steel or quenched-and-tempered alloy steel.
The previous heat treatment is also important. A component that has already been hardened and tempered must be stress relieved without unintentionally altering its established mechanical properties.
Welding can produce significant residual stresses and distortion because the weld region experiences highly localized heating and cooling. Post-weld heat treatment may be specified for particular materials, thicknesses, joint configurations or codes.
For pressure equipment, structural fabrication and other code-controlled applications, the applicable welding procedure and governing standard should take priority over a generic calculator estimate.
Machining can expose or redistribute residual stresses, particularly when material has been heavily cold worked, forged, rolled or previously heat treated.
Stress relieving before precision machining can sometimes improve dimensional stability. The exact procedure depends on material condition, section size and the dimensional requirements of the finished component.
Thicker components generally require more time for the entire section to reach the selected temperature. The temperature itself is primarily grade-dependent, while heating and holding time are strongly influenced by section size and furnace conditions.
This calculator therefore uses thickness mainly to produce a preliminary planning hold time rather than changing the fundamental metallurgical temperature range solely because the part is thicker.
This calculator provides an estimated starting range for preliminary engineering evaluation. It is not a certified heat-treatment specification.
What temperature is normally used for stress relieving steel?
Many carbon and low-alloy steels are stress relieved somewhere around 500–650 °C, but the appropriate range depends on the steel grade and its prior condition.
Does stress relieving make steel softer?
It can change hardness and mechanical properties, especially when performed at higher temperatures, so the treatment must be selected with the existing material condition in mind.
Is stress relieving the same as annealing?
No. Stress relieving primarily targets residual stresses, while annealing is normally intended to produce more substantial microstructural and property changes.
How long should steel be held during stress relieving?
Hold time depends on grade, section thickness, furnace conditions and the applicable specification. This calculator provides only a preliminary planning estimate.
Can welded steel be stress relieved?
Yes, where the material and applicable procedure permit it. Welded fabrication may have specific post-weld heat-treatment requirements.
Can I use this calculator for pressure vessels or safety-critical parts?
No. Those applications require the applicable code, qualified procedure and material-specific requirements to control the heat treatment.