Type: #12 x 3", 410 Stainless Steel, Bright Finish. | Screw Length: 3"(excluding the head height); Hex Head Diameter: 7.9mm; Head Washer Diameter: 10.5mm; Head Height: 5.1mm. | Quantity: 30 PCS; External Hex Drive Size: 8mm. | The drilling tek screws are 100% 410 stainless steel which is one of the highest forms of corrosion resistant steel. | Ideal use for wood, metal or other tough materials and known for their effecient application performance and endurance.