Multi Pro 1200/1250 Page 2 -- 3 Product Records and Maintenance
Torque Specifications
Recommended fastener torque values are listed in the
followingtables.Forcriticalapplications, asdetermined
byToro,eithertherecommendedtorqueoratorquethat
is unique to the application is clearly identified and spe-
cified in this Service Manual.
These Torque Specifications for the installation and
tightening offasteners shall apply to all fasteners which
donothave a specificrequirementidentified inthisSer-
vice Manual. The following factors shall be considered
when applying torque: cleanliness of the fastener, use
of a thread sealant (e.g. Loctite), degree of lubrication
onthe fastener, presenceof aprevailingtorque feature,
hardnessofthesurfaceunderneaththefastener’shead
or similar condition which affects the installation.
Asnotedinthefollowingtables,torquevaluesshouldbe
reduced by 25% for lubricated fasteners to achieve
the similar stress as a dry fastener. Torque values may
also have to be reduced when the fastener is threaded
into aluminum or brass. The s pecific torque value
should be determined based on the aluminum or brass
material strength, fastener size, length of thread en-
gagement, etc.
The standard method of verifying torque shall be per-
formed by marking a line on the fastener (head or nut)
and mating part, then back off fastener 1/4 of a turn.
Measurethetorquerequiredtotightenthefasteneruntil
the lines match up.
Fastener Identification
Figure 1
Grade 1 Grade 5 Grade 8
Inch Series Bolts and Screws
Figure 2
Class 8.8 Class 10.9
Metric Bolts and Screws
Using a Torque Wrench with an Offset Wrench
Useofanoffsetwrench(e.g.crowfootwrench)willaffect
torquewrenchcalibration duetothe effectivechange of
torquewrenchlength.Whenusingatorquewrenchwith
an offset wrench, multiply the listed torque recommen-
dation by the calculated torque conversion factor (Fig.
3) to determine proper tightening torque. Tightening
torque when using a torque wrench with an offset
wrench will be lower than the listed torque recommen-
dation.
Example: The measured effective length of the torque
wrench (distance from the center of the handle to the
center of the square drive) is 18”.
Themeasuredeffectivelengthofthetorquewrenchwith
the offset w rench installed (distance from the center of
the handle to the center of the offset wrench) is 19”.
The calculated torque conversion factor for this torque
wrenchwiththisoffsetwrenchwouldbe18/19=0.947.
If the listed torque recommendation for a fastener is
from 76 to 94 ft--lb, the proper torque when using this
torque wrench with an offset wrench would be from 72
to 89 ft--lb.
Figure 3
(effective length of
torque wrench)
TORQUE CONVERSION FACTOR = A / B
A
B
(effective length of torque
Torque wrenchOffset wrench
wrench + offset wrench)
Product Records
and Maintenance
To Next Page
Loading...
