Master Lock shot its own padlock to prove it was tough

By the early 1970s Master Lock competed in a padlock market where every manufacturer's advertising made the same generic durability claims, tough, secure, reliable, with no way for a skeptical television audience to distinguish which claims were true. Advertising research consistently shows durability claims are among the least persuasive ad content precisely because any manufacturer can make them regardless of whether they're accurate.

For Super Bowl VIII in January 1974, Master Lock aired a 30-second commercial with no celebrity, no jingle and almost no spoken claim: a marksman loads a .30 caliber rifle, aims, and fires directly at a Master Lock padlock. The bullet visibly punches a hole through the lock's body. The lock does not open. The tagline, "Tough Under Fire," appears on screen.

The commercial's entire persuasive power came from replacing an assertion with an unstaged-looking demonstration: rather than telling viewers the lock was tough, it showed the lock surviving the single most dramatic test a padlock could plausibly face, gunfire, and let the visual evidence make the argument advertising copy alone could not. The ad ran through Super Bowls from 1974 to 1983, then continued in variant forms through 1985 and beyond, with Master Lock reportedly directing nearly its entire annual marketing budget toward this single recurring spot rather than a broader campaign.

Replaced the claim with a demonstration: shot its own padlock on camera, letting the visual evidence of survival make the argument that copy alone could not.

The rifle shot was a visible, extreme test that viewers could not dismiss as staged.

The lock surviving shifted belief from trusting the advertiser to trusting their own eyes.

The test was more extreme than real use, implying ordinary wear was trivial.

The dramatic visual made the ad memorable, so it ran for years and built brand recognition.

When a claim is easy to doubt, show it surviving a visible, extreme test instead of asserting it.

After its 1974 'Tough Under Fire' Super Bowl spot showed a rifle shot fail to open the lock, sales grew from $35M in 1973 to $200M by 1994. Became a landmark case study in advertising for demonstration-based persuasion, cited alongside Timex's torture-test commercials as proof that visibly destructive product tests build more consumer trust than any spoken durability claim, and the campaign is still referenced in marketing courses today.