Thiadiazole (Metal Deactivator)
Thiadiazole (DMTD derivative) — a direct-use metal deactivator and copper corrosion inhibitor that protects yellow metals, with supplementary anti-wear and antioxidant character.
The direct-use copper deactivator for yellow-metal protection
Unlike the sulfonic acid and anhydride intermediates, thiadiazole is a direct-use additive — a metal deactivator that protects copper and yellow metals from corrosion.
Thiadiazole (a DMTD — 2,5-dimercapto-1,3,4-thiadiazole — derivative) is a direct-use metal deactivator and copper corrosion inhibitor. It forms a protective film on copper and other yellow metals, preventing the corrosion that active sulphur (from EP additives) can cause and passing the copper strip corrosion test. It also contributes supplementary anti-wear and antioxidant character. Unlike the sulfonic acid and anhydride intermediates in this range, thiadiazole is added directly to finished lubricants — gear oils, greases, industrial and hydraulic oils. It is part of the specialty additives range and is widely referenced across gear and grease formulations.
Thiadiazole (Metal Deactivator) — typical properties
Representative typical values for thiadiazole metal deactivator. Indicative only — exact values vary by grade and are confirmed on the TDS and batch COA.
| Property | Typical Value | Method / Note |
|---|---|---|
| Appearance | Amber to brown liquid | Visual |
| Active type | Thiadiazole (DMTD derivative) | Metal deactivator |
| Copper corrosion protection | Excellent | Passes Cu strip |
| Nitrogen/sulphur | Present | Active structure |
| Supplementary function | AW + AO character | Multifunctional |
| Flash point (COC) | > ~150 °C | ASTM D92 |
| Function | Metal deactivator | Direct-use |
Typical values for guidance only — not a specification. Request the TDS for the specific grade you need; the COA reports actual measured values for your batch.
Where thiadiazole metal deactivator is used
Industrial Gear Oils
Protects bronze worm gears from EP sulphur. See industrial & marine.
Gear Oils (GL-4/GL-5)
Protects yellow-metal synchronizers. See transmission fluid additives.
Greases
Copper protection in EP greases. See grease additives.
Hydraulic & Industrial Oils
Yellow-metal protection in hydraulic and circulating oils.
Why formulators choose thiadiazole metal deactivator
Excellent copper protection
Forms a protective film on yellow metals — passes the copper strip corrosion test.
Direct-use additive
Added directly to finished lubricants, not an intermediate for further reaction.
Multifunctional
Supplementary anti-wear and antioxidant character beyond metal deactivation.
From sample drum to ISO tank
Sinolook supplies thiadiazole metal deactivator at any scale, from formulation samples to commercial bulk, to over 60 countries.
Frequently asked questions
What is thiadiazole used for?
Why do EP gear oils need a copper deactivator?
Is thiadiazole an intermediate or a finished additive?
What is DMTD?
Can Sinolook provide TDS, MSDS and COA?
Request thiadiazole metal deactivator from Sinolook
Tell us your target grade, application and volume — we'll send the TDS, a batch COA and a delivered quotation within 24 hours.
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