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PA-8
GENERAL IN FORMATION
Figure 14—Model Identification; (C Models)
Figure 15—Model Identification (P6 Models)
has nearly the same diameter and has 25.4 threads per
inch. The thread pitch is in between the customary
coarse and fine thread pitches.
Metric and customary thread notations, differ slightly.
The difference is shown in figure 16.
identifications embossed on each bolt head. Markings
correspond; |to two lines less than the actual grade
(i.e.gradeij7:bplt will exhibit 5 embossed radial lines on
the bolt |.Head). Some metric nuts are marked with a
single dipitj lstrength identification number on the nut
face. To review the different strength markings avail
able, refer to figure 17.
When replacing metric fasteners, be careful to use
bolts and nuts of the same strength or greater than the
original fasteners (the same number marking or higher).
Likewise', ;it is important to select replacement fasteners
of the bdrrept size. Correct replacement metric fasten
ers available in the aftermarket parts channels were
designed; to metric standards of countries other than the
United States and may be of a lower strength, may not
have the numbered head marking system, and may be
of a different thread pitch. The metric fasteners used on
GM products are designed to new,, international stan
dards that may not yet be manufactured by some
non-domestic bolt and nut suppliers. "
FASTENER STRENGTH
IDENTIFICATION
Most commonly used metric fastener strength proper
ty classes are 9.8 and 10.9 with the class identification
embossed on the head of each bolt. Customary (inch)
strength classes range from grade 2 to 8 with radial line
PREVAILING
TORQUE FAS
A prevailing torque nut is designed to develop an
interference between the nut and bolt threads. This is
most often accomplished by distortion of the top of an
all-metai nut or by using a nylon patch on the threads in
the middle of the hex flat. A nylon insert may also be
CUSTOMARY
METRIC
1/4
—
20
M6.0
X
1
THREAD MAJOR
DIAMETER IN INCHES
NUMBER OF THREADS
PER INCH
THREAD MAJOR DIAMETER
IN M ILUM ETERS
DISTANCE BETWEEN
THREADS IN MILLIMETERS
THREAD PITCH
V1262
Figure 16—Thread Notation
Summary of Contents for C Series 1993
Page 1: ......
Page 12: ...OA 6 GENERAL INFORMATION Figure 11 Allison Transmission I D Location ...
Page 44: ...3B1A 2 POWER STEERING GEAR UNIT REPAIR Figure 1 710 Power Steering Gear ...
Page 62: ......
Page 75: ...3B3 2 POWER STEERING COMPONENTS TRW ROSS ...
Page 121: ...5H 16 AIR BRAKE VALVES Figure 21 Bendix Proportioning Relay Valve Components ...
Page 147: ...5J 10 AIR COMPRESSOR AND GOVERNOR 286 F9051 Figure 18 Bendix BX 2150 Compressor Components i ...
Page 204: ...MODEL 295 TBI UNIT 6C1 3 F7973 Figure 3 Model 295 TBL Unit ...
Page 251: ...6D4 6 37 MT STARTER MOTORS V3022 Figure 8 37 MT Components ...