COMBUSTION GP-EXHAUST 3550883 - Caterpillar

Illustration 1 g03012597
Example of a bolt with a black coating that is a poor electrical conductorTo minimize damage from rust and corrosion, many fasteners have black coatings that resist electrical conductivity in addition to resisting corrosion. Do not use such fasteners for electrical terminals or electrical grounding.Fasteners that provide good electrical conductivity have silver-colored zinc plating.Direct contact between terminals or a terminal-to-ground boss is recommended. Refer to Illustration 2
Illustration 2 g03012656
(1) Stud (2) Nut (3) Washer (4) Ring terminal (5) BossTable 1 lists some nuts and washers that are commonly used for electrical grounds. The low torque is recommended so that the ring terminals are not damaged.
Table 1
Fastener     Size     Low Torque    
5C-2890 Nut     M6     6 1 N m (53 8 lb in)    
1A-8912 Washer    
5C-7261 Nut     M8    
15 3 N m (11 2 lb ft)    
8F-7242 Washer    
8T-4133 Nut     M10    
30 7 N m (22 5 lb ft)    
7P-1695 Washer    
8T-4244 Nut     M12    
50 10 N m (37 7 lb ft)    
4B-4280 Washer