Most #10 metal roofing screws use a 1/4 inch hex head, requiring a 1/4 inch magnetic hex bit. #12 and #14 metal roofing screws use a 5/16 inch hex head. Check the hex head size on your specific screws before ordering.

Magnetic hex bits hold the screw on the bit tip during positioning, allowing one-handed screw placement on a roof. Without magnetics, the screw falls off the bit repeatedly when working overhead or on a slope.

Magnetic bits gradually lose magnetism over extended use and exposure to impact force. You can remagnetize a bit by stroking it with a strong rare-earth magnet. Keep magnetic bits separate from metal objects that cause demagnetization.

The size refers to the hex socket that fits over the screw head. 1/4 inch fits #10 metal roofing screw heads. 5/16 inch fits #12 and #14 roofing screw heads. Using the wrong size will not drive the screw correctly.

Yes. Magnetic hex bits with a 1/4 inch quick-change shank are compatible with impact drivers. However, for metal roofing screws, a controlled torque screw gun is preferred over an impact driver to avoid over-driving and compressing the EPDM washer.

Replace the bit when the hex socket shows visible rounding at the corners, which causes slipping on the screw head, or when the magnetic hold becomes too weak to hold a loaded roofing screw in a horizontal or downward orientation.

Magnetic hex bits are typically available in 1-inch and 2-inch lengths. Longer bits allow driving screws at a comfortable working distance without bending forward, which is useful when installing screws on steep roof pitches.

Magnetic hex bits are designed for hex washer head fasteners. Lag screw heads are also hex, so a correctly sized magnetic hex bit will work for lag screws, though lags typically require a socket wrench for the torque levels involved.

Our magnetic hex bits have a 1/4 inch quick-change hex shank that snaps into any drill or driver with a standard quick-change bit holder. No chuck key is required - simply push in and the bit locks automatically.

Yes. Standard hex driver bits are not magnetic and do not hold the screw. Magnetic hex bits have a magnet built into the socket that holds the screw head in place during positioning and driving, which is essential for overhead or angled installation work.