ISO 439:2020 specifies a gravimetric method for the determination of the silicon content in steel and cast iron.
The method is applicable to silicon contents between 0,10 % (mass fraction) and 5,0 % {mass fraction).
NOTE For samples containing molybdenum, niobium, tantalum, titanium, tungsten, zirconium or high levels of chromium, the results are less accurate than for unalloyed matrixes.
![ISO 439:2020](https://www.365standards.com/wp-content/uploads/2023/03/ISO-439-2020.png)