nickel or alloys with more than 40% nickel by weight; alloys with more than 25% nickel and 20% chromium by weight; fluoropolymers; glass or glass-lined (including vitrified or enamelled coating); graphite or carbon-graphite; tantalum or tantalum alloys; titanium or titanium alloys; zirconium or zirconium alloys; ceramics; ferrosilicon; or niobium (columbium) or niobium alloys.
(ب) سبائك بها أكثر من 25% نيكل و 20% كروم بالوزن؛