Fastener; Fastener Strength Identification - PREVOST H3-41 Maintenance Manual

SECTION 00 : GENERAL INFORMATION

5. FASTENER

5.1 FASTENER STRENGTH IDENTIFICATION

Most commonly used metric fastener strength
property 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 identification
embossed on each bolt head actual grade (i.e.,
a grade 7 bolt will have 5 embossed radial lines
on the bolt head). Some metric nuts will be
marked with single digit strength identification
numbers on the nut face. Figure 13 shows the
different strength markings. When replacing
metric fasteners, be careful to use fasteners of
the same or greater strength than the original
fasteners (the same number marking or higher).
It is also important to select replacement
fasteners of the correct size. Correct
replacement fasteners are available through the
parts division. Some metric fasteners available
in after-market parts sources 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.
10 |
PA1615 Maintenance Manual All Series Section 00 revised September 2016