Stripped a bolt on a Cessna 172 because I used my landscaping elbow grease

I was torquing down a panel on a 172 last Wednesday and just went at it like I do when I'm tightening down a fence post. Snapped the bolt clean off at 40 inch-pounds. My lead mechanic laughed and said “This ain't a flower bed, Betty.” Learned that aircraft parts need a feather touch and a torque wrench you actually trust. Any of you guys keep a second cheap torque wrench just for the small stuff so you don't wreck another bolt?

3 comments

3 Comments

mitchell.shane2mo ago

Ah man, that sucks big time. Honestly, I felt that one in my soul. You're not alone in learning that lesson the hard way. Torquing an aircraft part is like trying to pet a scared cat, you gotta be super gentle or you mess it up. @the_richard knows what's up with the beam-style wrench idea. I've never thought of that for the tiny stuff but it makes total sense. Ngl, after my first snapped bolt I just started going super slow and double checking every click on my wrench. It's a pain but it beats drilling out a broken bolt any day of the week.

schmidt.blake8d ago

Got a buddy who snapped a bolt clean off on a flap actuator last year. He was using a cheap click torque wrench that hadn't been tested in probably five years. Spent the whole afternoon drilling out the broken piece and then had to re-tap the hole since he messed the threads up too. After that he bought one of those beam style wrenches, said he wished he'd done it years ago. Ever have a wrench that just didn't feel right even when it clicked?

the_richard2mo ago

You mentioned "a torque wrench you actually trust" and that's the real issue nobody's talking about. Those cheap click-type wrenches drift out of calibration after a few drops on the hangar floor, and I guarantee most guys have never had theirs tested. I keep a beam-style wrench for anything below 50 inch-pounds because they don't lie to you when the spring gets tired.