SRB8
Cone 8 · Bends 1300°C (2372°F) at 300°C/hr, measured in a gas-fired kiln · 28.6 mm (1⅛ in) tall, ceramic · Sized for the Dawson Kiln-Sitter shut-off device · Tapered — placement under the sensing rod is worth about half a cone · Deforms 7 to 10°C (12 to 18°F) earlier than a self-supporting cone · Chart values assume a 23.8 mm (15/16 in) mounting height · Contains crystalline silica — do not grind or breathe the dust
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Bends at 1300°C (2372°F) at 300°C/hr. Sized for the Dawson Kiln-Sitter, where the sensing rod presses it to about a 90° bend and cuts the power. For porcelain, stoneware, china and floor tile.
Cone 8 in Orton's small regular (SRB) series, sized for the Dawson Kiln-Sitter rather than the kiln shelf. It bends at 1300°C (2372°F) at 300°C/hr, the only rate Orton publishes for this size, measured in a gas-fired kiln. The taper matters: the thin end under the sensing rod fires cooler, the thick end hotter, worth about half a cone either way. Small cones deform 7 to 10°C (12 to 18°F) earlier than a self-supporting cone, so never substitute a self-supporting figure for one of these. If a firing comes out short, Orton's instruction is to load the next cone hotter into the shut-off and let a cone on the kiln shelf settle the question.
