Centerline #8 x 1-1/4'' Flat Head Square X Self-Countersinking Fluted-Tip Wood Screws, Black, 100-Pack

Tooth-like nibs under the head allow the screw to countersink itself- Square X head accepts both square drive and Phillips bits.

Ultimate Square Drive Flat Head Screws #8

Centerline #8 x 3'' Flat Head Square X Self-Countersinking Fluted-Tip Wood Screws, Zinc, 100-Pack : Industrial & Scientific

Centerline #8 x 1-1/2'' Flat Head Square X Self-Countersinking Fluted-Tip Wood Screws, Zinc, 100-Pack: : Industrial & Scientific

Highland Woodworking Winter 2013 Catalog by Highland Woodworking - Issuu

8 Flat Head Square Drive Wood Screw Zinc Plated - BC Fasteners

Zinc-Plated Wood Screw, Flat Head With Nibs, Quadrex Drive, Coarse Thread, Type 17 Point - Onward Hardware

Centerline #6 x 5/8'' Flat Head Square X Wood Screws, Brass Plated, 100-Pack - Rockler

Simpson Strong Tie, PDF, Screw

1000) Square Drive Flat Head 8 x 1-1/4 Type 17 Wood Screws Zinc Plated #8 - Lexar Industrial

8 x 1-1/4'' Flat Head Star Drive Fluted-Tip Wood Screws, Exterior Bronze Ceramic, 100-Pack - Rockler

8 x 1'' Flat Head Square X Self-Countersinking Fluted-Tip Wood Screws, Black, 100-Pack - Rockler