เซรามิกวิกิพีเดีย. PARTICLE SIZE AND UNFIRED STRENGTH Clay Particle Size Analysis (1 Less than size in Micron) Unfired Strength Lb/in2 (kg/cm2) 10 5 2 1 0.5 China Clay (Cornwall) 825020 250 (17.6) Black Ball Clay (Devon)- 82 74 60 750 (53) Blue Ball …