Stanley Fatmax Stud Finder 400 Manual (2025)

The exact center of the stud is the midpoint between your two pencil marks.

: The midpoint between your two marks is the safest place to drive a screw. How To Use a Stanley Stud Finder

Curiosity (and a bit of structural anxiety) got the better of him. He didn't drill. Instead, he used a small drywall saw to peek behind the mark. There were no wires. Instead, tucked into the hollow space between two perfectly placed studs, was a rusted tin box wedged against an old copper pipe—the culprit behind the erratic sensor readings.

Disclaimer: This article is a general guide based on typical stud finder operation. Always refer to the original manual that came with your specific Stanley FatMax 400 model for exact safety instructions and specifications.