Product Description The Hillman Group 82209 8 x 1-1/4-Inch Modified Truss Lath Self Piercing Screw, 100-Pack From the Manufacturer These Self-Piercing Screws feature an undercut head design to help provide great holding power and stability. There is no pre-drilling required, making these easy to use. Ideally, they are used for thin metal such as sheet metal and duct work.