Where does each technical statement come from?
The encyclopedia separates sourced values, calculations, family guidance and internal comparison indices so that estimates cannot be mistaken for test data.
Evidence labels
Sourced values originate from standards, producer data sheets or identified technical references. Calculated values depend on the stated formula and inputs. Family guidance supports screening only.
Documented calculations
CE(IIW) is intended for preliminary assessment of carbon and low-alloy steels. PREN is a comparative stainless-steel pitting index. Neither result is a service guarantee.
CE = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15
PREN = %Cr + 3.3 × %Mo + 16 × %N
Use engineering calculatorImportant limits
When grade- and condition-specific data are unavailable, the encyclopedia does not invent Charpy, Izod, KIC, allowable stress, creep life, CCT/TTT curves or guaranteed heat-treatment temperatures.