Backer-On No. 9 S X 2-1/4 in. L Star Round Head Cement Board Screws 100 pk

The Backer-On 2-1/4 in. Cement Board Screws are designed for attaching HardieBacker or equivalent fiber cement backerboard to wood or light gauge steel studs. Backer-On's patented serrated head design countersinks for flush seating at any angle, providing a smooth surface for tile.
Serrated head design for flush seating even at an angle
Star drive with T-25 bit provides Stikfit for easy one-handed installation and eliminates cam-outs
Patented sharp point offers immediate pick-up and eliminates the need to pre-drill
Serrated thread forms require less torque for faster installation
Patented design allows attaching close to edge on cement board, drastically reducing fractures or blow outs