Recommended Nut Torques (Inch-Pounds) - Piper Navajo Chieftain PA-31-350 Service Manual

NOTE
If the bolt is stationary and the nut is
torqued. use the lower side of the torque
range If the nut is stationary and the
bolt is torque, use the higher side of the
torque range
5. When torquing castellated nuts. begin with minimum torque plus
friction drag torque. but do not exceed maximum torque plus friction
drag torque when trying to align slot on nut with the hole in the bolt
shank. If they do not align. change washers and try again. When
using castellated nuts on moveable joints. do not torque asdescribed
above. Tighten nuts only to remove looseness in the joint and then
install the cotter pin.
6. After the final torque has been applied the nut or bolt or screws if no
nut is used) should be permanently marked red and should not be
further tightened or disturbed.
NOTE
SEE NOTE
8
-32
10 -24
1/4-20
5/16-18
3/8-16
7/16-14
1/2-13
9/16-12
5/8-11
3/4-10
7/8- 9
1 -8
1-1/8-8
1 1/4-8
NAVAJO CHIEFTAIN SERVICE MANUAL
TABLE II-II. RECOMMENDED NUT TORQUES (Inch-Pounds)
TORQUES: The importnce
of correct application cannot be overemphasized.
Undertorque can result in unnecessary wear of nuts and bolts
as
well as the
parts
they
are
holding together. When insufficient pressure are applied. uneven
loads will be transmitted throughout the assembly which may result in excessive
wear or premature failure due to fatigue. Overtorque can be equally damaging
because of failure of a bolt or nut from overstressing the threaded areas. There
are a few simple. but very important, procedures that should be followed to
assure that the correct torque is applied:
1. Calibrate the torque wrench periodically to assure accuracy: and
recheck frequently.
2. Unless otherwise specified. torque all nuts to the applicable torque in
the Recommended Nut Chart. If the nut (or the bolt) is listed but not its
mating fastener, use the lower torque specified for the listed nut (or
bolt).
NOTE
If normal operation requires movement
between any of the components being
clamped together. tighten the nut Ior
bolt) without regard to the nut torque
chart, to insure intended operation of
the assembly
3. Bolt and nut threads should be clean and dry unless otherwise
specified. If the threads are to be lubricated and no torque is specified.
reduce the recommended nut torque (plus the friction drag torque) by
50%.
4 For other bolt sizes. determine the friction drag torque by turning the
nut to near contact with the bearing surface. Attach a scale type
torque wrench to the nut and determine the torque required to turn
the nut on the bolt (before the nut makes contact with the bearing
surface) Add this. the friction drag torque. to the specified torque to
get the final torque
COARSE THREAD SERIES
BOLTS
Steel Tension
AN 3 thru AN 20
AN 42 thru AN 49
AN 73 thru AN 81
AN 173 thru AN 186
MS 20033 thru MS 20046
MS 20073
MS 20074
AN 509 NK9
MS 24694
AN 525 NK525
MS 27039
NUTS
Steel Tension
Steel Shear
AN 310
AN 320
AN 315
AN 364
AN 363
NAS 1022
AN 365 MS 17826
NAS 1021
MS 20364
MS 17825
MS 21045
MS 20365
MS 20500
NAS 679
Men. Max.
Nut and bolt sizes 8 through 7/16
include friction
drag torque values.
Revised: 2/8/82
1B6
HANDLING AND SERVICING