The Simpson Strong-Tie Strong-Drive SDHR Combo-Head Screw is made for serious wood projects like cross-laminated timber (CLT), mass timber, and other big framing jobs.

The unique combo-head design gives you flexibility, with a choice to drive it with either a hex bit or a T40 6-lobe bit. A knurled shank helps lock the screw in place, and the sharp Type-17 point starts fast, reduces driving torque, and often eliminates the need for predrilling. Finished with a blue zinc coating, these screws are perfect for tough interior jobs where strength and reliability matter most.

Key Features

• Made for Big Projects Ideal for CLT, mass timber, and other engineered wood connections.
• Dual Drive Options Drive with either a hex bit or T40 6-lobe bit, whichever works best for you and your project.
• Strong Hold Partially threaded shank with knurl pulls members together and resists pull-out.
• Secure Drive Deep T40 6-lobe recess for consistent engagement (replacement bit: BIT40T-134-R2).
• Interior Ready Blue zinc coating offers corrosion resistance for dry, indoor applications.