Sr.No. Characteristics 80/100 60/70 1 Specific gravity at 27 C min 0.98 0.99 2 Water percent by wt.max 0.2 O.2 3 Flash point, C 175 175 4 Softening point C 软化点 35-50 40-55 5 Penetration ay 25 c ,100g 5 sec in1/100cm 80-100 60-70 6 Ductility at 27 C, in cm.min 75 75 7 Loss of heating, percentage by wt.max 1 1 8 Penetration of residue 60 60 9 Percent by wt.slouble in carbon di-sulphide,min 99 99