During his 19 seasons on NCIS, Mark Harmon infused pieces of his real life into his character, Leroy Jethro Gibbs. Off duty from solving high-stakes cases, Gibbs spent his free time building sailboats in his basement – each named with personal meaning, like Kelly, in honor of his late daughter.

Just as Gibbs preferred hand tools over power tools, Harmon shares that same devotion. On the show, Gibbs was notoriously protective of his tools, once blowing up in season 18 when he discovered they’d been moved – not realizing a serial k1ller was behind it. Off-screen, Harmon is just as particular.

In a 2014 interview with Craig Ferguson, Harmon’s wife, actress Pam Dawber, poked fun at his obsession. She recalled how he owns “probably 17 hammers” and insists they be put back exactly as found. “All I ask is that you just put things back the way you found them,” Harmon tells her.

Before acting, Harmon worked as a carpenter, taking woodworking jobs to pay the bills before landing his breakout role on St. Elsewhere. While neither Harmon nor Gibbs pursued carpentry professionally, both treated it as more than a hobby – a grounding passion. Gibbs’ last boat, Rule 91, symbolized his fresh start in retirement.

Now, with NCIS: Origins exploring Gibbs’ early years, Harmon’s love for woodworking remains tied to his most iconic role. In many ways, both actor and character turned their garages into man-caves of craftsmanship.