Stud Finder Modes
Affiliate link — we may earn a commissionModern stud finders have multiple detection modes for different materials behind the wall. Stud mode detects the density change at wood or metal framing, typically from 3/4-inch to 1-1/2-inch deep. Deep scan mode reaches through thicker walls, usually up to 1-1/2 inches. AC wire detection senses live electrical wiring so you don't drill into it. Metal mode detects pipes, rebar, and metal conduit. Some models add a center-finding mode that marks both edges of the stud and calculates the center automatically. Cheap models only have stud mode. Mid-range models add AC detection.
Why It Matters
Drilling into a live wire or a water pipe turns a simple shelf install into an emergency. AC wire detection isn't optional. Metal detection catches copper pipes that stud mode misses. Spend the $15 extra for a multi-mode finder.