(1) Torque wrenches must be those specified
and forces must be applied at the handle
grip. The use of handle extensions will
Torque wrenches are precision
change applied torque to bolt.
instruments and must be handled
with care. To ensure accuracy,
(2) All handles must be parallel to the step
wrench during final tightening. Multiplier
schedule basis. Whenever there
reaction bars may be misaligned no more
is a possibility that a torque
than 30 degrees without causing serious
wrench may have been either
error in torque.
overstressed or damaged, it
should immediately be removed
(3) Multiplier reaction bar handles must be
from service until recalibrated.
propped or supported within outer 1/4 of
When using a torque wrench, any
handle length, or serious under or over
erratic or jerking motion can
tightening will occur.
result in the application of
excessive or improper torque.
The inner race of bearing is secured to carrier
frame by forty 1.25-in. x 7 in. grade 8 bolts
and nuts. The outer race of bearing is secured
to superstructure by twenty-four 1.25-in. x 4
ALWAYS use a slow, even
in. grade 8 bolts.
movement and STOP when
the predetermined value has
b. Torque Values.
been reached. If it is reported
by the crane operator or
Preliminary torque on bolts is 1571 ft-lbs (2090
suspected that the crane has
Nm). With two multipliers, set torque wrench
for 128 ft-lbs (170 Nm). With six-in. step
been overloaded beyond the
wrench, set torque wrench for 94 ft-lbs (125
capacities specified above the
Nm). With eighteen-in. step wrench, set
bold line on the cranes'
torque wrench 62 ft-lbs (82 Nm).
turntable bolts must be
c. Tools Required.
inspected for looseness and
retorqued to specifications.
Tools required are listed at the beginning of
Turntable bolts should be
torqued following preliminary
figures in this Section. When
calculated wrench settings
are valid only when following
conditions are met.
*U.S. GOVERNMENT PRINTING OFFICE: 1995 O - 167-711