GRAPHITE CRUCIBLES SIZE 4/0 This is a new size 4/0 graphite crucible Will tolerate thermal shock This resistant crucible often called black lead, withstands heat up to 3,000 degreesF (1,649 degreesC) It measures approximately 3 1/8" (79 mm) tall and the diameter tapers from about 2 3/8" to 1 3/4" (60 x 44.5 mm)