Timco Metal Construction Timber to Heavy Section Screws - Countersunk - Wing-Tip - Self-Drilling - Exterior - Silver Organic 5.5 x 120 - 100 Pieces Heating Filters or simply for situations where

or simply for situations where the water needs isolating on a regular basis

Compatible with all metals and materials commonly used in central heating systems

2 recess for a positive drive

5mm spline

Timco Metal Construction Timber to Heavy Section Screws - Countersunk - Wing-Tip - Self-Drilling - Exterior - Silver Organic 5.5 x 120 - 100 Pieces Heating Filters or simply for situations whereDescription Timco Metal Construction Timber to Heavy Section Screws Countersunk Wing Tip Self Drilling Exterior Silver Organic 5. 5 x 120 100 Pieces product description: Specifically designed to attach wood to metal (Max. 12mm). Metric thread with wings designed to ream out the timber, so the screw can achieve Max. R. P. M. without burning out. When the wings hit the metal they will break off to permit the thread to self tap into the metal. NOTE: