... surface based on different sizes.1. Main types:Iron-Chromium-Aluminium(FeCrAl) series:0Cr25Al5, 0Cr23Al5, Kanthal D, 0Cr2Al6 ... , Kanthal A1, 0Cr27Al7Mo2, 0Cr21Al4, 0Cr19Al3, 1Cr13Al4, 0Cr15Al5, etcNickle-Chromium(NiCr) Series:Cr20Ni80, Cr30Ni70, Cr15Ni60, Cr20Ni35, Cr25Ni20, Cr20Ni302. ... magneticNot magneticWeak magneticWeak magnetic Iron-Chromium-Aluminium(Fe-Cr-Al)Electric Resistance Strip