Properties Value remark Piling density/gcm 3 0.002-0.005 Product density/gcm 3 0.8-1.7 Carbon content % í² 98 >99.5%is called Crozzle(ash) % ín0.35 High purity graphite Sulphur content í¦ 1000ppm Chlorine content í¦ 50ppm Melting point 0 c 3650 Hardness 21~33 Tensile strength(mpa) 8~10 Compressive strength(mpa) 70~110 Compressibility % í² 15 Resilient rate % í² 30 Ph 0-14 Friction coefficient 0.149 Wooden box