Set of 10 screws with double thread for solid materials. To screw the pin it is necessary a 6mm spanner. Head imprint: star To screw the screw it is necessary a hole previously drilled in the concrete, brick or the dowel is obligatory or and the wood or without dowel or . Partially threaded screw developed for better assembly to durable elements Use: Fixing to the wall or ceiling. Dowel screws without or with dowels are recognized for their reliability, simplicity and solidity Application: steel and wood structures, building construction, concrete slabs, carpentry, carpentry, plumbing, interior and exterior fittings, renovation, installations solar on roofs Hanging stud bolt for joining elements in high hardness - these screws are very resistant to tearing as well as breaking. Unit weight: 13 g. Material: Galvanized Steel. Silver color Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-YJL official store