Operation - Stanley IW12 Service Manual

WRENCH TORQUE INFORMATION
FACTORS THAT AFFECT TORQUE
An impact wrench is a rotary hammer that impacts the head
of a bolt or nut. It does not apply a slow steady torque as a
standard torque wrench. Therefore, several factors affect
the result of torque when using impact wrenches:
1. LONG BOLTS. Long bolts having high-friction threads
with lubrication under the bolt head or associated nut can
twist when impacted, then untwist before the next impact.
This will especially happen if there is low friction between
the bolt head or nut and the mating surface.
2. HEAVY, LOOSE OR MULTIPLE ADAPTERS. Heavy,
loose or multiple adapters between the wrench and socket
can dissipate the intensity of the impact to the bolt head or
nut.
3. AMOUNT OF IMPACT. Maximum torque results can be
obtained by allowing continuous impacting of the socket
against the bolt head or nut for at least 10 seconds.
4. HYDRAULIC FLOW RATE. If the fl ow rate to the tool is
too low, the hammer (or impact) speed is reduced. If the
fl ow is correct, a change in the relief pressure does not af-
fect the impact force. Poorly designed hydraulic circuits can
result in lower fl ow rates and reduced impact speeds when
pressure is required during impacting.
BOLT GRADE AND THREAD
RECOMMENDATIONS
Allowable bolt torque is limited by both bolt thread diameter
and grade of steel in the bolt. The IW12 Impact Wrench
is recommended for use on the following bolt grade and
thread sizes:
SAE Grade 2 1 to 1-1/2 inch / 25/38 mm
SAE Grade 5 3/4 to 1-1/4 inch / 19-32 mm
SAE Grade 8 5/8 to 1 inch / 16-25 mm
PREOPERATION PROCEDURES
CHECK POWER SOURCE
1. Using a calibrated fl ow meter and pressure gauge, check
that the hydraulic power source develops a fl ow of 4-12
gpm/15-45 lpm at 1000-2000 psi/70-140 bar.

OPERATION

2. Make certain that the hydraulic power source is equipped
with a relief valve set to open at 2100 psi/145 bar minimum.
CONNECT HOSES
1. Wipe all hose couplers with a clean, lint-free cloth before
making connections.
2. Connect hoses from the hydraulic power source to the
tool fi ttings or quick disconnects. It is good practice to con-
nect the return hose fi rst and disconnect it last to minimize
or eliminate trapped pressure within the wrench.
3. Observe the fl ow indicators stamped on the main body
assembly and the hose couplers to ensure that the fl ow is
in the proper directions. The female couple on the tools "IN"
port is the inlet (pressure) coupler.
Note:
If the uncoupled hoses are left in the sun, pressure
increase within the hoses can make them diffi cult to
connect. Whenever possible, connect the free ends of
hoses together.
The IW12 is designed for 3/4-inch square sockets and
accessories. Adapter part number 06790 or equivalent will
permit the use of 5/8-inch quick change drive attachments.
Normal applications include installation or removal of fas-
teners requiring torque in the range of 300-1200 ft lb/407-
1627 Nm and auger bit wood boring. DO NOT use the
wrench as a hammer drill for metal drilling.
During normal operation it is common to see some grease
leakage from around the anvil during hard use. Refer to
the IW12 Service Manual for the correct lubrication proce-
dures.
1. Observe all Safety Precautions.
2. Move the hydraulic circuit control valve to the "ON" posi-
tion to operate the wrench.
Always use sockets and accessories designed for
impact type applications. DO NOT USE STANDARD
SOCKETS OR ACCESSORIES. THESE CAN
CRACK OR FRACTURE DURING OPERATION.
10
WRENCH OPERATION
WARNING