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DAILY 4x4 ‒ GUIDELINES FOR BODYBUILDERS
CHASSIS INTERVENTIONS
2.2 DRILLS ON THE CHASSIS
– Printed 692.68.999 – 3 Ed. - Base 08-2020
2.2.2 Screws and nuts
We generally recommend the use of the same type and class of screws and nuts as those employed for similar anchorages on the
original vehicle (see Table 2.3).
Table 2.3 - Screws resistance classes
Resistance class Use
Breaking strength
[N/mm
2
]
Yield stress
[N/mm
2
]
8.8
Intermediate resistance screws (cross members,
shear resistant plates, brackets)
800 640
10.9
High resistance screws (springs supports, stabilizer
bars and shock absorbers)
1000 900
The screws belonging to classes 8.8 and 10.9 must be well cleaned and, for applications with diameter ≤ 6 mm, protection FeZnNi
7 IV S is recommended; for diameters > 6 mm, protection GEO-8 is recommended.
Screw treatment allowed is Geomet or zinc coating. Geomet treated screws are discouraged when using them in welding opera-
tions.
Use flange headed screws and nuts if there is sufficient space.
Use nuts with an anti-unscrewing system and keep in mind that the tightening torque must be applied to the nut.
2.2.3 Welding
▶ When welding, drilling, milling and cutting near brake hoses and electrical wires, be sure to ad-
opt appropriate precautions for their protection; disconnect these parts if necessary (observe
the specifications indicated in Chapters 2.15 and 5.4).
Welds are allowed:
● in side member unions for elongations or trimming;
● in the application of corner reinforcements in the area regarding side member modification, as hereafter specified (see Figure
3).
91448
Figure 3
The following instructions must be respected when performing electric arc welding and in order to protect electrical components
and ECUs:
● before disconnecting the power cables ensure there are no active electric users;
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