Nickel is a primary cost driver for stainless steel and superalloys.
About 800H/HT|Dual-designation Incoloy 800H and 800HT. The HT variant adds tighter controls on aluminum and titanium content for even better creep properties above 1100°F. In practice, most production meets both specs. See 800H for details.
About Plate|Thick flat stock, generally 3/16" and up, used for machined base plates, fixture plates, wear surfaces, and structural fabrication. Heavier grades get milled, drilled, and tapped directly.