TB 43-0218
TABLE 3-1. TORQUE RANGES
STATED RANGE
MOST EFFECTIVE RANGE
0-200 LB/IN
50-150 LB/IN
0-600 LB/FT
50-450 LB/FT
0-170 LB/FT
44-131 LB/FT
15-75 LB/FT
30-60 LB/FT
7.
Installation and Torquing.
a. Matching Nuts. Matching nuts require a minimum height (see Figure 1) equal to the basic diameter of the bolt.
The same is true of tapped holes. In tapped softer materials, the depth of the tapped hole should be 1-1/2 times the
basic diameter of the bolt.
b. Thread Protrusion. In all installations, bolts, studs and screws must extend through the nut at least a length
equivalent to two complete threads (see Figure1). This applies to both self-locking and plain nuts.
c. Torquing Self-Locking Nuts. To obtain the correct recommended torque value on self-locking nuts, the nut must
be tightened until it is one turn from the beginning of seating. At this point, if the torque is less than 1/3 of the
recommended torque, it should be disregarded and the nut tightened to the recommended torque value. If the torque
is 1/3 or more of the recommended torque, it should be added to the recommended torque. Example: The
recommended torque is 50 to 70 LB/IN (6 to 8 NM). The torque at one turn from seating is 30 LB/IN (3 NM). The
correct torque wrench reading would be 80 to 100 LB/IN (9 to 11 NM).
d. Retorquing Fasteners. Procedures intended for installing metal fasteners can cause an incorrect reading when
used to check or retorque already installed fasteners during maintenance. Before checking or retorquing an already
installed threaded fastener, first mark the fastener and its companion components so the marks are in line. Second,
back it off a turn to loosen it. Torque it to the specification with an even steady pull on the torque wrench. The
marks should be in line; if not, the marks will indicate the fastener was under or over torqued.
e. Standard Torque Charts. Standard torque charts have been established for dry and wet torque conditions.
Surface variations such as thread roughness, scale paint, lubrication (oil, grease, etc.) hardening and plating may
alter these values considerably. The following are standard torque charts. If vehicle technical manuals list different
torques always use the readings listed in the vehicle technical manuals.
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