WD-40's Ultra-Secret Formula Guarded in San Diego Bank Vault

Only a handful of people have ever seen the original handwritten recipe for the iconic lubricant.

Jan. 31, 2026 at 1:31pm

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The original formula for the 70-year-old WD-40 lubricant is kept under lock and key in a concealed Bank of America vault in San Diego. Access to the handwritten notebook containing the successful "40th" formula and 39 failed attempts is tightly restricted, with only a few top WD-40 executives ever granted permission to view it. The recipe is considered one of the company's most closely guarded trade secrets.

Why it matters

WD-40 is an iconic product used for everything from loosening rusted bolts to removing gum, and the formula accounts for nearly 80% of the company's revenue. Keeping the original recipe a closely guarded secret is crucial to maintaining WD-40's market dominance and preventing competitors from replicating the product.

The details

The notebook containing the WD-40 formula is stored in a concealed vault at a Bank of America branch in San Diego. Access to the vault is tightly controlled, requiring a special key held by the company's top lawyer and nondisclosure agreements from anyone granted entry. Even senior WD-40 scientists have never seen the original formula, instead working from a coded version. The notebook itself contains the successful "40th" formula as well as the 39 failed attempts that came before it.

  • WD-40 was first introduced 70 years ago.

The players

Steve Brass

CEO of WD-40 Company, who was granted access to view the original formula about 18 months ago.

Sara Hyzer

Chief financial officer of WD-40 Company, who viewed the original formula alongside CEO Steve Brass.

Meghan Lieb

Head of R&D at WD-40 Company, who has worked at the company for two decades but has never seen the original formula.

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What they’re saying

“It was like getting into Fort Knox.”

— Steve Brass, CEO (Wall Street Journal)

What’s next

WD-40 CEO Steve Brass says he may add a few long-serving employees to the exclusive group allowed to view the original formula if the company ever reaches $1 billion in sales, but he insists he will not grant access to the company's own board of directors.

The takeaway

The ultra-secretive nature of WD-40's original formula, which is kept in a concealed bank vault and viewed by only a handful of top executives, highlights the company's commitment to protecting its iconic product and maintaining its market dominance in the lubricant industry.