To the untrained eye, one screw is as good as another, but

those with a little more awareness have a better chance of

realising that choosing the right screw for a particular job

can mean the difference between a project succeeding and

failing.

The industrial and construction sectors have literally hundreds

of different types of screws and fasteners to select from; each

type suited for a particular usage e.g. lubricated timber

decking screws for quicker driving into outdoor decking,

self-drilling screws for the convenience of not having to drill

pilot holes and even screws that work specifically with the

mechanical properties of plastics.

Before you can choose the best screw for a job you should

consider the characteristics you desire in a screw such as:

• Does it need to be waterproof to avoid corrosion from

moisture?

• Does the screw head need to be flush with material once it's

screwed into place?

• Does the screw need to be protected from vandalism or

unauthorised removal?

• Is the screw to be used in wood, metal or perhaps plastic?

• What length of screw is required?

For different types of material there tends to be a different

type of screw. Take the following as examples:

• Wood screws – designed to perform best in all types of wood

including hardwood, MDF and chipboard. Smaller screws have less

chance of splitting wood, but if you're using larger screws

and/or working near the end of a piece of wood then it's often

safer to drill a pilot hole first.

• Floor screws – these will cope with the issue of different

expansion rates so are best used for securing timber or

chipboard to steel supports. Made by a process that ensures a

hard exterior whilst retaining a tough, flexible core.

• Self-drilling screws – designed for convenience as only a

screwdriver is required. These screws drill their own holes and

form their own mating threads ensuring the best fit in a single

attempt.

• Timber decking screws – specially designed to deal with

outdoor conditions with durable, protective coatings.

• Frame anchor screws – designed for fixing window and door

frames made from PVC-U, wood or aluminium directly to brickwork

without the need for plugs or nylon anchors.

A general rule of thumb for determining an appropriate length

of you should look for a screw length that will allow

two-thirds of its length to be embedded into the material being

fastened to. So, for example, if you're fastening a 1-inch thick

piece of timber to a wooden post then you should be looking at

embedding 2-inches of the screw into the post. That means you

would require a screw length of 3-inches.

All good screw suppliers will be able to advise on the

appropriate screws for your task. The important thing is to

appreciate that not all screws are the same and that using the

right screw can mean a secure installation, whilst the wrong

screw can mean in an accident waiting to happen.