HAMMER DRILL 1.Material :high strength steel,surface treatment 2.Super hardness HAMMER DRILL1.Material :high strength steel,surface treatment2.Super hardnesssize:6''*110 ,6''*160 ,6.5''*110 ,6.5''*160 ,8''*110 ,8''*160 ,10''*110 , 10''*160 , 12''*160 ,14''*160 ,16''*160mm HAMMER DRILL