Book spec snapped my bolt, should I trust my wrist instead?

I was doing a flap track fitting on a 737 at the hangar in Tulsa last month. The manual said 120 inch pounds, I set my clicker wrench, and the bolt gave way before the click even came. Turned out the threads had corrosion buildup that made the friction lie about the real tension. I backed out the broken piece, chased the threads, put in a new bolt with fresh lube, and it torqued fine. But it got me thinking, when a bolt snaps at book spec on a clean-looking install, do you trust your calibrated wrench or your hands telling you something is off? I've seen old timers who never use a torque wrench on small fasteners and they swear by feel. Have you ever had a failure exactly at spec and what did you do differently the next time?

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the_matthew1mo ago

Had a similar head scratcher on a Cessna wing bolt years back. Book said 90 inch pounds and my beam wrench read dead on but the bolt stretched like taffy. Pulled it and found the hole was drilled slightly oversize from the factory, so the bolt was never really clamping right. New bolt did the same thing. Ended up using a helicoil and it finally torqued clean. Sometimes the hardware is fine and the hole itself is lying to you.

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