These carbon steel self-drilling screws with wings are electro-zinc plated and are designed for wood-to-metal applications without the need to pre-drill. They have a 12-24 thread size, and a length of three inches. These screws feature a #3 socket wafer head and a Teks 4 drill point. They have a drilling and tapping capacity range from 0.125 to 0.250 inches and a wood attachment range of 1/4-inch to two inches. There are 1,000 self-drilling screws per box.