Excellent Potassium Sulfide Resistance Gold & Silver Antitarnish - China Factory Suppliers for Plating Solutions
Product Brief
Core Product Advantages
Conventional silver anti-tarnish agents turn black within 30 seconds to 3 minutes in 5% K2S solution, while 315T delivers superior anti-sulfur performance. At 25°C room temperature, silver coatings stay discoloration-free for 5–10 minutes (longer protection with thicker silver plating). It effectively blocks sulfur ion erosion from air, packaging materials and harsh industrial environments to eliminate spotting and blackening.
The protective film features stable high-temperature resistance. Silver-plated workpieces treated with 315T retain bright metallic luster after 10 minutes baking at 280°C without yellowing, blackening or dullness. It fully adapts to post-processes such as SMT reflow soldering and high-temperature assembly, avoiding mass product scrapping caused by high-temperature discoloration.
It isolates moisture and corrosive media in the air efficiently. Gold-plated workpieces treated with 315T pass 72-hour neutral salt spray test without corrosion, spots or fading, extending service life greatly for gold products used in humid, coastal and corrosive working conditions.
The ultra-thin transparent film carries no insulating barrier. It will not raise contact resistance of precision contacts, nor damage welding performance or signal transmission stability. It fully meets conductivity and soldering requirements of high-end precision electronic components, eliminating cold joints and signal drift issues.
Wide Application Industries & Workpieces
Suitable for copper substrates pre-nickel plated + bright silver-plated automotive connectors, signal terminals and communication conductive components. It prevents silver layer blackening during long-term storage and outdoor service to guarantee stable conductive performance.
Designed for thin silver-plated moving/static contacts and switch shrapnel. It enhances anti-tarnish capacity of thin silver coatings, prevents contact resistance drift and ensures stable, sensitive electrical signal transmission.
Compatible with 925 silver ornaments, electroplated silver artworks and metal decorative parts. It blocks sulfide from rubber packaging and ambient air to avoid spotted blackening, maintains long-term mirror brightness and reduces after-sales return rates.
Specially formulated for anti-corrosion and anti-tarnish protection of PCB gold-plated and partially silver-plated pads. It solves gold pitting corrosion in humid environments while preserving excellent solderability to reject welding failure and scrap.
Ideal for thick silver-plated RF cavities, antenna assemblies and industrial parts operating under high-temperature conditions. It satisfies dual protection demands of sulfur resistance and high temperature resistance for complex harsh industrial environments.
Solution Composition & Operating Parameters
| Parameter | Working Range | Optimum Condition |
|---|---|---|
| 315T Concentration | 30 - 80 ml/L | 50 ml/L |
| Operating Temperature | 45 - 50℃ | -- |
| pH Value | 7.0 | |
| Soaking Time | Over 5 minutes | -- |
Complete Process Flow:
Immerse fully cleaned workpieces in diluted 315T working solution for about 5 minutes. Workpieces can be wet or dry before dipping, but thorough cleaning is mandatory.
Take out dipped workpieces and rinse in room-temperature clean water for 0.5–1 minute. Avoid over-rinsing. If low water temperature causes poor surface appearance, slightly heat the rinse water to improve finish.
Drain or spin dry cleaned parts, spread out on clean racks, then blow-dry or oven-dry below 65℃.
315T can also be used with electrolysis to achieve superior performance. Stainless steel or titanium mesh can be used as anode, with voltage set at 2–3V.
Product Performance Test Data
Storage Instructions
Frequently Asked Questions
Under a 5% potassium sulfide (K2S) test at 25°C, silver coatings treated with 315T remain discoloration-free for 5 to 10 minutes. The exact anti-tarnish duration positively correlates with the thickness of the silver plating.
Yes. Treated silver-plated parts can resist oxidation and discoloration even after baking at 280°C for 10 minutes. This makes it fully compatible with high-temperature assembly processes such as SMT reflow soldering.
No. The ultra-thin transparent film creates no insulating barrier. It does not increase contact resistance or compromise signal transmission stability and welding performance, making it ideal for high-end electronic connectors and PCBs.
Gold-plated workpieces treated with 315T pass a 72-hour neutral salt spray test without showing any signs of corrosion, fading, or spots, providing excellent protection in humid and coastal environments.
The optimum concentration is 50 ml/L (working range: 30 - 80 ml/L) at an operating temperature of 45 - 50°C and a neutral pH value of 7.0. The workpieces should be soaked in the solution for over 5 minutes.
It should be stored in a clean, dry warehouse with temperatures maintained between 5°C and 35°C. Avoid direct sunlight exposure and use within its valid shelf life for the best performance.