Corrosion
Potential
When metals contact each other under moist conditions, a voltage may be generated, depending on the metals (galvanic reaction; remember the copper and zinc battery in school?) If the metals touch each other, a current is generated which will corrode one of them. This table shows how common construction metals react when in contact with one other under moist conditions.
|
How Metals React On Contact | |||||||||
|
Materials |
Aluminum |
Brass |
Bronze |
Copper |
Galv. Steel |
Iron or |
Lead |
Stainless |
Zinc |
|
Aluminum |
OK |
NG |
NG |
NG |
OK |
? |
? |
OK |
OK |
|
Copper |
NG |
? |
? |
OK |
? |
NG |
? |
NG |
NG |
|
Galv. Steel |
OK |
? |
? |
? |
OK |
? |
OK |
? |
OK |
|
Lead |
? |
? |
? |
? |
OK |
OK |
OK |
? |
OK |
|
Stainless Steel (active) |
OK |
NG |
NG |
NG |
? |
? |
? |
OK |
NG |
|
Zinc |
OK |
NG |
NG |
NG |
OK |
NG |
OK |
NG |
OK |
|
Legend |
OK = will not corrode |
? = may corrode |
NG = will corrode | ||||||
Example: the brass and aluminum intersection shows as NG (No Good), therefore corrosion will develop (the aluminum will be eaten away), so aluminum should not be fastened using brass screws (use OK stainless steel screws instead).
Copyright 2000, New York Association of In-house Locksmiths, Inc. All rights reserved.