| Symbol | deff |
|---|---|
| Unit | mm |
| Attribute-ID | effective diameter |
| Numeric ID | 1391 |
| Value Type | PMTechValue |
The technological size factor K1 roughly takes into account that the achievable hardness (and thus also the yield strength and fatigue strength) during tempering and/or the core hardness during case hardening decrease as the diameter increases. The technological size factor K1 is the same for all stress types and is calculated using the decisive diameter deff for the heat treatment. deff depends on the component shape and size, and is used to consider the influence of size or component shape on the cooling process during hardening/tempering.