TM-9-2350-311-20-2

HOWITZER, MEDIUM, SELF-PROPELLED, 155MM; M109A2, M109A3, M109A4 AND M109A5

TECHNICAL MANUAL; UNIT MAINTENANCE MANUAL FOR CAB, ARMAMENT, SIGHTING AND FIRE CONTROL, ELEVATING AND TRAVERSING SYSTEMS AND ASSOCIATED COMPONENTS

DECEMBER 1993

TM-9-2350-311-20-2 - Page 782 of 828

TM 9–2350–311–20–2

F–2

Change 2

F–1

TORQUE LIMITS

Table F–1 lists wet torque limits. Wet torque limits are used on screws that have high-pressure lubricants applied to the

threads.

F–2

HOW TO USE TORQUE TABLE

a.

Measure diameter of screw you are installing.

b.

Count the number of threads per inch or use a pitch gage.

c.

Under heading “SIZE”, look down the left hand column until you find the diameter of the screw being installed (there will

usually be two lines beginning with the same size).

d.

In the second column under “SIZE”, find the number of threads per inch that matches the number of threads counted in

step b.

e.

To find the grade screw being installed, match markings on the head to the correct picture of cap screw head markings

on the torque table.

f.

Look down the column under the picture found in step e, until you find the torque limit in lb-ft or N

.

m for the diameter and

threads per inch of the screw being installed.

NOTE

Manufacturer’s cap screw head marking may vary. These are all SAE grade 5 (3 line).

MEASURING DIAMETER

COUNTING THREADS/IN.

SAE GRADE 5 (3 LINE) MARKINGS