Copyright 2021. All rights reserved by Rockmore International.
2
2.3 – Initiating the ROK LT Hammer (continued)
should be held upright so that the oil can lubricate all internal components. Please reference section 3.1
below for minimum amounts of rock drill oil required for all ROK LT Series DTH Hammers.
The percussive mechanism begins to operate as the air supply is turned on and when the drill bit is
pushed firmly into the hammer. Excessive pressure is not needed to initiate the hammer. Rotate the
hammer clockwise at approximately 30-rpm and the hammer will begin. The DTH bit will now push into
the Driver Sub and percussive action begins. When the hammer is lifted from the rock face, the DTH bit
extends from the Driver Sub and percussive action ceases. Extra air will pass through the hammer,
which can be used to flush the hole clean. By adjusting airflow, air pressure, feed force and rotation
optimal penetration rate and productivity can be achieved.
Rotation speed should be selected according to drilling conditions and drill rig capabilities. Please be
aware that excessive rotation may result in premature wear on the drill bit and not better penetration rates.
3. HAMMER MAINTENANCE:
3.1 – Lubrication
Proper lubrication is necessary for effective and efficient drilling operations. Inadequate amounts of
lubrication may damage the hammer resulting in premature hammer failure. With insufficient amounts of
lubrication the temperatures of the Piston surface can exceed 1400
°
F (752
°
C). These excessive
temperatures generate heat checks (fine cracks) on the surface finish that may propagate through impact
and initiate Piston failure. Improper oil selection may result in decarburization, which greatly reduces the
tensile strength of the material allowing fractures to initiate.
The minimum amount of rock drill oil required for the operation of all ROK LT Series DTH hammers is
listed below.
Oil Consumption @ 145 psi
(10.0 Bar)
Hammer
l/hr
gal/hr
ROK 20LT
0.1
0.03
ROK 30LT
0.1
0.03
Pneumatic rock drill oils are the only acceptable lubricants for DTH hammers. In ambient temperatures of
80
°
Fahrenheit (27
°
Celsius) or higher, use SAE 50 rock drill oil.
Several acceptable rock drill oils are listed below:
Medium SAE 30
Heavy SAE 50
Exxon
Aroc 150
Aroc 302
Shell
Torcula 150
Torcula 320
Texaco
Rock Drill Lube 100
Rock Drill Lube 320
Chevron
Vistac 150
Vistac 320
Rockmore Hammer Guard
