Black Diamond Drilling DTH Down the Hole hammers

DTH Hammer information and product list

The optimum range of hole size for blast hole drilling with DTH is 90 mm to 254 mm (3 ½”–10″). Smaller blast holes are generally drilled using tophammer, and larger holes generally use rotary machines.

In other applications, like foundation drilling, DTH hammers can be used with single bit in hole sizes up to . 750 mm (30″). With multiple hammer units CD (Cluster drills) drill holes up to 70″ or 1778 mm.

As a rule of thumb, the smallest hole diameter a DTH hammer can drill is its nominal size. A 4 inch hammer will drill a 4 inch (102 mm) hole. The limiting factor is the outside diameter of the hammer, because, as hole diameter reduces, airflow is restricted. Maximum hole size for production drilling is the nominal hammer size plus 1 inch, so for a 4 inch hammer the maximum hole size is 5 inch (127–130 mm).

Choosing the right hammer is largely determined by hole size and type of rock formation. Ideally, the size of the hammer should match the required hole dimension as closely as possible, leaving just enough space for cuttings to evacuate the hole.

HammerBR2ADHD3.5HK4DHD45HQL40AHQL50HK5QHD55HQL60HQL60AHQL80HD85HK9QHSD10HSD12HK12YN125-R
Recommended bit size, mm7692-105112-127140-152165-178203-229216-229245-305305-445305-350305-445
Bit ShankBR2ADHD3.5DHD340AQL40QL50DHD350QL60QL80DHD380QL80SD10SD12HY12NUMA125R
External diameter, mm6382100100101126.5127.5126.5148146185185203225275275275
Length excl. thread, mm
(Less bit)
8378559151032.5105711479351167112111821471148713451413168015901812
Hammer weight, kg
(Less bit)
14.12537.540.64171.667.677.2105105203206228303526510.2546
Package case size(L)910
(W)90
(H)120
(L)1200
(W)110
(H)140
(L)1010
(W)130
(H)160
(L)1080
(W)125
(H)134
(L)1150
(W)130
(H)160
(L)1290
(W)150
(H)175
(L)1100
(W)155
(H)180
(L)1290
(W)150
(H)175
(L)1270
(W)170
(H)200
(L)1260
(W)180
(H)200
(L)1440
(W)230
(H)270
(L)1560
(W)230
(H)270
(L)1500
(W)240
(H)280
(L)1620
(W)275
(H)290
(L)1880
(W)320
(H)320
(L)1665
(W)320
(H)360
(L)1880
(W)310
(H)310
Top Sub threadRD502-3/8" API REG3-1/2" API REG4-1/2" API REG6-5/8" API REG6-5/8" API REG
7-5/8" API REG
6-5/8"
API REG
Working Pressure, PSI80-170150-250200-300250-350300-350300-380300-380150-350200-350
Air consumption, CFM250-350300-400500-700500-800600-900950-1200950-12001000-18001200-1500800-1800
Piston diameter, mm42.765828080104102100122121150150165185225
Piston weight, kg1.75.19.299171716242438425068110111111
Wrench flat, mmL47
W50
L57
W35
L74.5
W45
L64
W40
NO
wrench
flat
L89
W60
L88
W50
L89
W60
L101
W65
L101
W60
L128
W70
L140
W70
L128
W70
L140
W70
L140
W70
L140
W70
L140
L70
Feed force, kN2~63~85~156~257~2010~2515~3020~35
Rotation speed, r/min30-703-9025-8020-7025-6020-6015-35
Drilling conditions and project specifications may require larger air package to be used

DTH Bits information and products list

Hole Openers

Drill Pipes

Adapters

Breakout Bench