The most widely used material for Wood Screws is mild steel. It is quite a weak metal and rusts easily.

When using screws which are likely to get damp, choose those which are plated with a corrosion-resistant finish such as cadmium, sheradized or bright zinc plated. You could also use screws made of a non-rusting metal like aluminum alloy, brass or stainless steel. These last three types are expensive; aluminum alloy and brass screws are particularly weak and sometimes break when screwing them into hardwood the secret is to put in a mild steel screw first.

Supascrcws and Mastascrcws combine extra strength with bright zinc plating.

There are a few other important things to consider when selecting screw finishes:

o When fixing metal things, beware of chemical interaction between the metal and the screw finish. Interaction between steel and aluminum alloy is particularly common and the resulting corrosion may make the screws jam. Wherever possible choose screws with the same finish as the metal being fixed

o Untreated mild steel screws will react chemically with some hardwoods - particularly afrormosia, idigbo and oak -causing discoloration of the wood. Use brass or stainless steel screws instead

o Occasionally the appearance of the screw head is of paramount importance. Brass and steel screws plated with chrome or nickel (both shiny) and Pozidriv and Supadriv screws with a bright zinc finish are all available. Chrome-plated screws with domed heads are available for fixing mirror and bathroom tittings the domed head is actually separate from the screw head and has to be screwed into a tiny threaded hole in the screw head once the screw is fitted.

Screw sizes

In addition to length (measured from the point of the screw to the surface the screw is driven into, not always the overall length), the diameter or gauge needs to be specified too. The gauge indicates the diameter of the screw and the bigger numbers indicate bigger sizes.

Now you know about how to fix screws and bolts. You should also know how to choose screws and bolts and for efficient work, you should also know how to use Hex Head Screw in the right way.