Toro Groundsmaster 1200 Service Manual page 19

Torque Specifications
Calculating the Torque Values When Using a Drive-Adapter Wrench
Groundsmaster® 1200 Pull-Behind Rotary Mower
18235SL Rev A
The recommended fastener torque values are listed in the following tables. For
critical applications, as determined by Toro, either the recommended torque or
a torque that is unique to the application is clearly identified and specified in
this manual.
These torque specifications for the installation and tightening of the fasteners will
apply to all the fasteners which do not have a specific requirement identified in
this manual. The following factors must be considered when applying the torque:
cleanliness of the fastener, use of a liquid thread sealant (e.g., Loctite), degree of
lubrication on the fastener, presence of a prevailing torque feature (e.g., Nylock
nut), hardness of the surface underneath the head of the fastener, or any similar
condition which affects the installation.
As noted in the following tables, the torque values should be reduced by 25% for
the lubricated fasteners to achieve the same stress as a dry fastener. The torque
values must be reduced when the fastener is threaded into the aluminum or
brass. The specific torque value should be determined based on the aluminum
or brass material strength, fastener size, length of thread engagement, etc.
g205924
1. Torque wrench
2. Drive-adapter wrench (crows foot)
Using a drive-adapter wrench (e.g., crowfoot wrench) in any position other than
90° and 270° to the frame of the torque wrench will affect the measured torque
value because of the effective length (lever) changes. When using a torque
wrench with a drive-adapter, multiply the listed torque recommendation by the
calculated torque conversion factor
torque. When using a torque wrench with a drive-adapter wrench, the calculated
torque will be lower than the listed torque recommendation.
Example: The measured effective length of the torque wrench (distance from
the center of the handle to the center of the square drive) is 457 mm (18 inches).
The measured effective length of the torque wrench with the drive-adapter
wrench installed (distance from the center of the handle to the center of the
drive-adapter wrench) is 483 mm (19 inches).
The calculated torque conversion factor for this torque wrench with this
drive-adapter wrench would be 18/19 = 0.947.
If the listed torque recommendation for a fastener is 103 to 127 N∙m (76 to 94
ft-lb), the proper torque when using this torque wrench with a drive-adapter
wrench would be 98 to 121 N∙m (72 to 89 ft-lb).
Figure 4
Torque Conversion Factor = A / B
3. A (effective length of torque wrench)
4. B (effective length of torque wrench and
drive-adapter wrench combined)
(Figure 4) to determine proper tightening
Page 2–5 Specifications and Maintenance: Torque Specifications