It has a four sided square head at one end and a cup-shaped indentation at the other end

1 1/4 x 18 ITM SDS Plus Hammer Drill Bit X-Cutter

3/4-10 x 2 1/4 L9 Hex Cap Screw Yellow Zinc Plated Domestic USA (20)

1/4 x 3 1/4 Slotted Hex Hi-Low Thread Concrete Screws Blue Ceramic Coated (1000)

1/4 x 4 1/2 Simpson Strong-Drive® SDS Heavy-Duty Connector Screw Double-Barrier Coating - Pack (10) 7/8-9 Socket Cap Screws Alloy It has a four sided1 4 x 4 1 2 Simpson Strong Drive SDS Heavy Duty Connector Screw Double Barrier Coating Pack (10) . A 1? 4" diameter high strength structural wood screw ideal for various connector installations as well as wood to wood applications. Features: Patented 4 CUT point (coated version) and type 17 point (stainless version) enable easy driving with no pre drilling and minimal splitting Available with a double barrier coating and Type 316 stainless steel 3? 8"