Daihatsu F300 Service Manual page 1319

ENGINE MECHANICALS
TIGTENING TORQUE FOR MAIN COMPONENTS
1. When you want to find out a suitable tightening torque for a bolt. first determine the strength division of
the said bolt, using the table
below.
Then, locate suitable tightening torque in the tightening torque table
described later.
2. As for the tightening torque for a nut. find out suitable tightening torque in the same way as w·rth the
paragraph 1 above, based on the mating bolt.
3. Tightening torque posted in the workshop manual is a standard value for steel fasteners. It is, therefore,
necessary to modify these tightening torque when you tighten fasteners made of materials other then
steel.
This rule also applies to such instances where bolts are undergoing heat or other stress, such as vibratory
loads and so forth.
METHOD TO IDENTIFY STRENGTH DIVISION OF BOLTS
1. Identification Method by Checking Bolts Themselves
Configuration and how
to
determine
Strength Configuration and
how
to determine
strength division
divisiOll
strength division
®
Bolt having an 4 = 4T
~
embossed or 5 = 5T Welded
stamped figure at its 5
=
5T
...
head section
7::::. Tr
0
No mark
4T
'
No mark
Hexagon
...
C) Bolt having two
5T
Stud boh
embossed lines
at
its
head section
6T
'
Bolt having
about 2 mm
deep
recess at
0
[J8DI
one end or both
Bolt having three
ends
embossed lines at its
7T
head section
Strength
division
4T
4T
6T
•
•
2. Identification Method by Part Numbers
__,.,.
Hexagon Bolt
Stud Bolt
Part number 9 1 , 1 1
-·o·r_
Part number 9 1 1 1
1-406L
example example
r
Nominal
r
Nominal
length (mm)
length (mm)
Nominal
Nominal
diameter (mm)
diameter (rrm)
----iStrength divisio~J
ngth division
•=MII~i~~~,
~I
Nominal
diameter
Nominal length
I
Length
I
•
EM-178