The Strong-Drive SDCP Timber-CP screw is a structural fastener available in a variety of lengths and is designed for cross-laminated timber (CLT) and mass timber construction, as well as general interior applications. These partially-threaded, 0.315-in. and 0.394-in. diameter structural fasteners are designed to pull structural members together with superb holding power and excellent load capacity. The large, flat head and underhead nibs provide for clean countersinking, flush with the surface. Predrilling is not typically required. For interior and dry applications only. Strong-Drive® SDCP TIMBER-CP Screw — 0.315 in. x 8-5/8 in. T40, Yellow Zinc (50-Qty) (Pack of 6).