... lengths.button bits, cross type bits and chisel bits with(6,7,11,12 degree taper).Bit diameter:28mm-57mm.3. Extension drilling toolsButton ... .4. Down the hole hammers and DTH button bits (Down The Hole Drilling)Offer ir hammers,DHD3.5,DHD340a,DHD360,DHD380,and ... low pressure hammers CIR65a, CIR90, CIR110, CIR150,CIR170etc,DTH drill bits ...