General description Specifically designed to attach wood to metal (max. 4.0mm), the TIMCO Collated Self-Drilling Wing-Tip Steel to Timber Light Section Silver Screws feature a coarse self-tapping thread with wings that ream out the timber, allowing the screw to achieve maximum RPM without burning out. When the wings hit the metal, they break off to facilitate the installation process. Technical specifications Dimensions: 4.8 x 65 mm Material: Steel Thread type: Coarse self-tapping Max metal thickness: 4.0 mm