TB 43-0218
SECTION V. TORQUE LIMITS
8. General. This section provides general torque limits for screws used on Tank-Automotive Equipment. Special torque
limits are indicated in the maintenance procedures for applicable components. The general torque limits given in this
section shall be used when specific torque limits are not indicated in the maintenance procedure. These general torque
limits cannot be applied to screws that retain rubber components. The rubber components will be damaged before the
torque limit is reached. If a special torque limit is not given in the maintenance instructions, tighten the screw or nut until it
touches the metal surface, then tighten it one more turn.
9. Torque Limits. Table 5-1 lists dry torque limits. Dry torque limits are used on screws that do not have lubricants
applied to the threads. Table 5-2 lists wet torque limits. Wet torque limits are used on screws that have high pressure
lubricants applied to the threads. Table 5-3 lists torque limits for metric fasteners.
the same size).
10. How To Use Torque Table.
d. In the second column under SIZE, find the number
of threads per inch that matches the number of threads
you counted in step 2. (Not required for metric screws).
CAPSCREW HEAD MARKINGS
Manufacturer's marks
Metric screws are of three
may vary. These are all
grades: 8.8, 10.9, and 2.9.
SAE Grade 5 (3-line).
Grades & Manufacturer's
marks appear on the
a. Measure the diameter of the screw you are
screw head.
installing.
e. To find the grade screw you are installing, match
the markings on the head to the correct picture of
CAPSCREW HEAD MARKINGS on the torque table.
f.
Look down the column under the picture you found
in step 5 until you find the torque limit (IN/LB/Fr or NM)
b. Count the number of threads per inch.
for the diameter and threads per inch of the screw you
c. Under the heading SIZE, look down the left hand
are installing.
column until you find the diameter of the screw you are
installing (there will usually be two lines beginning with
8
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