POP NUT Brand Blind Rivet Nuts
• Strength Test Methods for POP NUT
• Surface Treatments of POP NUT for Use on Aluminum Materials
 Steel POP NUTAluminum material Galvanized layer
The zinc on the POP NUVM corrodes in the area contacting the aluminum
material. Once the POP NUT corrodes, the aluminum material will also
corrode. Although the degree of corrosion is small ond the combination of steel
POP NUT and aluminum materials is feasible in an indoor environment, caution
must be exercised in an outdoor environment.
Steel (Galvanized) POP NUITM and Aluminum Materials. Corrosion of the aluminum
material can be reduced by changing the surface treatment of the POP NUT.
[Surface Treatments for Use with Aluminum Materials]
- Dacro coating
- C + resin caating
- Alloy plating + resin coating
- Other surface treatments are also passible. For details,
please contact Thread-Rite.
Electrolytic Corrosion (Corrosion due to contad between different metals)
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• If different metals are immersed in a
conductive liquid in a condition whereby
they contact each other, the metal of the
lower potential (base metal) will become
the anode, while the metal af the higher
potential (nobler metal) will become the
cathode. The resulting ‘local battery” will
cause the anode metal to ionize and
dissolve (corrode). This farm of corrosion
is called galvanic corrosion or
electrochemical corrosion, or more
generally electrolytic corrosion. |
• Conditions That Promote Electrolytic Corrosion
(General Environment)
(1) Metals have a large potential difference
(2) High temperature, high humidity, high acidity
(3) Small area of plating an the anode metal
(4) Air containing salt |
• Allowable Combinations af Different Metals
The MlL-STD-17~A can be used only based on
limited metal combinations as shown in the
table below. Generally the electrode potential
of the mating metal should ideally be 0.1 Var or
higher. |
| Countermeasures to Electrolytic Corrosion |
- Select a nut of a material whase electric
potential is lower ar whose potential difference
from the mating material is small.
- Caat either the nut or base material with the
same material as the bose material or nut ar a
metal whose potential difference from the other
material is small (plating, etc.).
- Insulate the nut and base material by coating.
- Insert an insulating material, such as resin,
between the nut and base material (coating,
bush, etc.)
- Insert a metal having an intermediate
potential difference between the nut and base
material in between (plating, coating, bush, etc.)
- Make the nut the nobler metal.
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