Size Name:4.5 x 30 mm Wood Screw Multi-Purpose Pozi Screws can be used for more or less everything, e.g. Hardwood, softwood, MDF, Particleboard, chipboard, Fibreboard, Ply, Laminates, Plastics and PVCu. So the screws can be used for more or less for most of the DIY project work, except for the project you may need specialised screws like working on metal. The build quality is good too. It is claimed it is anti-corrosive and lasts up to 6 times longer than standard zinc coatings.Screws are used mostly for do-it-yourself work which confirms how popular and universal they are. They can be used with large number of materials such as hardwood, PVC and others. 'Galvanised' and 'Zinc Plated' processes are quite common to the procedure of zinc yellow passivation process of electroplating only difference is inclusion of a yellow colorant.Easy screwing and uncomplicated penetration are ensured by countersunk head. The highest power transmission is guaranteed with better stability on the cross-shaped head. They have an exceptional longevity because of their zinc and yellow passivation. The quality is extremely high with almost no rusting.