Galvanic Corrosion Protection
EXPANDING OPTIONS FOR FASTENING DISSIMILAR METALS
NYSHIELD® is effective in preventing galvanic corrosion between steel fasteners and the most extreme lightweight materials – which include both magnesium and carbon fiber. NYSHIELD® is applied very uniformly to the steel fastener surfaces that contact dissimilar materials, and shields / protects the least noble material. This product has minimal tension loss, even up to 150°C, and also has exceptional chemical resistance. It also adheres well to most substrates.
NYSHIELD® protects steel fasteners from galvanic corrosion in high risk material combinations:
- – CARBON FIBER
- – MAGNESIUM
- – ALUMINUM
- – CHROME PLATING
- – OTHERS
- Provides exceptional galvanic corrosion resistance (steel fasteners with magnesium or carbon fiber substrates)
- Provides general corrosion protection (15+ year vehicle life simulation)
- Coating Uniformity: typical thickness is 50-75 microns
- No interference with HEX or TORX drive
- Low tension loss at elevated temperatures (150°C)
- Adjustable Coefficient of Friction (typically between 0.10– 0.16)
- Excellent adhesion
- Exceptional chemical resistance
- Good toughness / durability
- Q: How is NYSHIELD® applied?
A: It is a powder that is sprayed onto parts that are then heated.
- Q: How hot does NYSHIELD® get during processing?
A: On average the curing temperature is 225°C (437°F) for a very brief time.
- Q: Why does NYSHIELD® prevent galvanic corrosion?
A: It acts as a barrier so that electrons do not travel between dissimilar materials.
- Q: What is needed for galvanic corrosion to occur?
A: Three things are needed: two dissimilar materials in proximity or direct contact with each other, and the presence of an electrolyte.
- Q: How thick is NYSHIELD®?
A: With normal processing, NYSHIELD® has a thickness between 40-80 microns.
- Q: Can NYSHIELD® be applied to internal drives, and if so, will the drives still fit?
A: Yes. Normally NYSHIELD® that is directed into internal drives is done at a lower thickness (40 microns or less) to accommodate drive fit, even for fasteners as small as M3’s. Nylok requests go/no-go gauges from fastener suppliers so that in-process inspections can occur during production per the manufacturing control plan.
- Q: Does NYSHIELD® get removed from bearing surfaces upon installation?
A: No. The only exception might be if the mating surface is extremely irregular or as jagged edges.
- Q: What is the temperature limit for NYSHIELD®?
A: This depends on the application. For example, if NYSHIELD® is applied under head and experiences a clamp load, testing has shown that no significant clamp load loss occurs up to at least 125°C.
- Q: What other temperature limitations are there to the product?
A: NYSHIELD® has been exposed to 195°C for 168 hours with no apparent changes in ductility. It has also been exposed to 233°C for 4 hours without same.
- Q: Is NYSHIELD® available in other colors?
A: Glossy black is the only option at present for NYSHIELD®.
- Q: Does NYSHIELD® provide a grounding path for electrical current?
A: No. NYSHIELD® is an electrical insulator.
- Q: What other applications are there for using NYSHIELD®?
A: As mentioned above, NYSHIELD® is a good electrical insulator, and can be used to isolate voltages (it has a high dielectric strength value).
- Q: Can NYSHIELD® be used as a sealant?
A: Nylok has various materials for sealing. However, NYSHIELD® has been tested in at least one very demanding sealing environment and sealed very well against helium. NYSHIELD® may be considered as a sealant if temperature ranges and chemical resistance of other Nylok sealants are not sufficient for the application at hand.
- Q: What platings/finishes are recommended for NYSHIELD® application?
A: The best plating/finish is electroplated zinc or zinc nickel. Other finishes are also suitable. Contact Nylok for more information.
- Q: Can topcoats be used in the plating/finish?
A: No. No topcoats or lubricants can be used in the applied plating/finish. The reason is that these topcoats often outgas and cause a blistered surface to appear instead of the normal, smooth NYSHIELD® coating. Also, topcoats diminish the adhesion of NYSHIELD® to the surface.
- Q: If no topcoats or lubricants can be used in the plating/finish, how is the coefficient of friction (COF) maintained?
A: Nylok applies surface modification over the top of NYSHIELD® to keep the COF within a specified range.
- Q: Can NYSHIELD® be used on brass? On stainless steel? On other metal substrates?
A: NYSHIELD® has been applied to metal substrates other than low-mid carbon steel. For more information, please contact Nylok with your specific application.
- Q: Do you sell NYSHIELD®? Or do we send you the parts and then Nylok coats them?
A: Typically, NYSHIELD® is applied at Nylok on specialized equipment.
- Q: How can I get samples processed?
A: Contact Nylok @ (586) 786-0100 or firstname.lastname@example.org to discuss your application prior to sending samples for NYSHIELD® processing.
- Corrosion Resistance (steel vs. carbon fiber, steel vs. magnesium) is exceptional after 15 year simulation exposure (GMW17026) (See download for results)
- Coefficient of Friction results are adjustable (typical range 0.10 – 0.16) (See download for results)
- Tension Loss Test & Results at: 150°C / 973hr: comparable to control bolt without NYSHIELD™ (See download for results)
- Tape Adhesion Test: 10 days @ 40°C in 100% RH chamber, cross hatch cut in coating/tape pull: no removal of coating (Per GMW14829) (See download for results)
- Chemical Resistance Tests: • 24 hour soak (engine oil, coolant, transmission fluid, power steering fluid, windshield washer fluid, vehicle cleaning agent, transit coating/protective wax, car shampoo, paintwork cleaning product) • 2 hour soak (E10 fuel, E85 fuel, diesel fuel, Windex, Rain-X, 2-in-1 glass cleaner, remover for transit coating, washer fluid) • 10 minute soak (tar and road oil cleaner, chrome cleaner) • Results: no visual change in coating appearance: no noticeable softening of coating (See download for results)
- Durability: Good corrosion resistance after coated fastener is subjected to drop test