Craftsman 320.27990 Operator's Manual page 13

INSTALLING FASTENERS
NOTE: Always keep the Impact Wrench at a right angle to the fastener to avoid
damaging the fastener head.
To fasten:
1.
Start threading the fastener by hand onto or into its threaded counterpart
(e.g. nut onto bolt, or bolt into nut or threaded hole).
2. With the proper impact socket securely mounted to the wrench, slide the
impact socket onto the nut or bolt head.
3 Hold the tool securely with both hands and depress the switch at '_j.
The impact socket will turn the fastener and impacting will begin once the
fastener encounters resistance.
A_, WARNING: Do not over-tighten, as the force of the Impact Wrench can
break the fastener.
To loosen:
1.
2
3.
With the proper impact socket securely mounted to the wrench, slide the
impact socket onto the bolt head.
Hold the tool securely with both hands and depress the switch at _.. The
tool will start to impact immediately.
Once the fastener has "broken loose," it will start to unthread. Be careful that
you do not allow a fastener to spin freely once it is no longer engaged with
its threaded counterpart, as it may be thrown out of the socket.
IMPACTING TECHNIQUES
The proper fastening torque may differ depending on the type or size of the bolt,
the material of the workpiece to be fastened, etc.
NOTE: Hold the tool straight along the axis of the bolt or nut.
NOTE: Excessive fastening torque may damage the bolt/nut or socket. Before
starting your job, always perform a test operation to determine the proper
fastening time for your bolt or nut.
Practice with various fasteners, noting the length of time required to reach the
desired torque. Check the tightness with a hand-torque wrench. If the fasteners
are too tight, reduce the impacting time. If they are not tight enough, increase
the impacting time.
Hold the tool firmly, and place the socket over the bolt or nut. Turn the tool on,
and fasten the bolt or nut to the proper torque.
The torque that is required to loosen a fastener averages 75% to 80% of the
tightening torque, depending on the condition of the contacting surfaces.
However, if rust or corrosion causes seizing, more torque may be required.
27990 ManuaLRevised_lO 1202 Page 13