OPERATION
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, sever- al factors affect the result of torque when using impact wrenches:
1.LONG BOLTS. Long bolts having
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 flow rate to the tool is too low, the hammer (or impact) speed is re- duced. If the flow is correct, a change in the relief pressure does not affect the impact force. Poorly designed hydraulic circuits can result in lower flow 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 di- ameter 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
SAE Grade 5 3/4 to
SAE Grade 8 5/8 to 1 inch /
PREOPERATION PROCEDURES
CHECK POWER SOURCE
1.Using a calibrated flow meter and pressure gauge, check that the hydraulic power source develops a flow of
140 bar.
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,
2.Connect hoses from the hydraulic power source to the tool fittings or quick disconnects. It is good prac- tice to connect the return hose first and disconnect it last to minimize or eliminate trapped pressure within the wrench.
WARNING
Always use sockets and accessories designed for impact type applications. DO NOT USE STANDARD SOCKETS OR ACCESSORIES. THESE CAN CRACK OR FRACTURE DURING OPERATION.
3.Observe the flow indicators stamped on the main body assembly and the hose couplers to ensure that the flow is in the proper directions. The female cou- ple on the tools “IN” port is the inlet (pressure) cou- pler.
NOTE:
If the uncoupled hoses are left in the sun, pressure increase within the hoses can make them difficult to connect. Whenever possible, connect the free ends of hoses together.
WRENCH OPERATION
The IW12 is designed for
Normal applications include installation or removal of fasteners requiring torque in the range of
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 lubrica- tion procedures.
1.Observe all Safety Precautions.
2.Move the hydraulic circuit control valve to the “ON” position to operate the wrench.
10 ► IW12 User Manual