SSB020
Cone 020 · Bends 626°C (1159°F) at 60°C/hr (medium) · Bends 638°C (1180°F) at 150°C/hr (fast) · No 15°C/hr figure published at this number · 63.5 mm (2½ in) tall, ceramic · Built-in base — no cone plaque, clay pat, or wire holder needed · Mounting height and 8° angle preset at the factory · Endpoint is a 90° bend, tip level with the base · Contains crystalline silica — do not grind or breathe the dust
$0
Bends at 626°C (1159°F) at 60°C/hr or 638°C (1180°F) at 150°C/hr. No 15°C/hr figure is published. The base is moulded in, so it needs no plaque or holder. For overglaze decoration, lusters, enamels and decals, and for glasswork.
Cone 020 in Orton's self-supporting (SSB) series. It bends at 626°C (1159°F) at 60°C/hr and 638°C (1180°F) at 150°C/hr, measured over the firing's last 100°C; Orton publishes no 15°C/hr figure at this number, so only those two rates apply. The patented base is moulded in, so it stands on the kiln shelf straight from the box, with no plaque or wire holder and no mounting angle to set. Those figures are not a tolerance: a cone measures heat-work, time and temperature combined, so the firing rate decides which number applies. Needing no mounting, it is the usual choice for witness cones and test firings, read at a 90° bend with the tip level with the base.
