Different types of screw do many different types of job and as with everything else in the Construction Industry and DIY world, the job is much much easier with the right tools, equipment and products.
Take a look at our table of screw sizes:
Screw sizes vary and generally the larger the number the bigger the screw. For example a number 6 screw is much smaller than a number 12 screw. There are many types of fixing for all types of material and circumstances so make sure you get the right one to make the job easy.
It is usually much easier to insert screws when you have drilled a pilot hole. This prevents the screw from binding. See how to drill the correct size pilot holes in our project page. Countersinking the screws also makes for a much neater job.
|Substrate/Finish||Type of screw||Reason||Internal||External|
|Hardwood||Twin thread||Ease of start up and driving||Zinc plated twinthread||Brass or Black Jappaned screws|
|Soft Wood||Single thread||Strength in position – High pull-out retention||Zinc plated countersunk||See above|
|Chipboard||Single thread||High pull-out retention||Chipboard Countersunk screws||Do not use chipboard outside unless covered|
|MDF||Single thread with twin thread start||Twin thread allows ease of start up and single thread provides high pull-out retention||MDF Countersunk screws||Do not use MDF outside unless covered|
|Wood – Traditional Finish||Single thread||Traditional finish required to product||Zinc or brass roundhead screws||Brass ditto|
|Masonry||Single thread – Case hardened with groove in thread to allow dust to escape||Single thread for hold and drive to grind into masonry||Concrete & Masonry self tapping screws||Frame screws and hammer fixings|
|Metal||Self tapper||Cut their own thread into metal||Self Tapping screws||Stainless steel self tappers|
|Plasterboard||Drywall screws||Sharp piercing point with twin thread and bugle head for flush finish. Can be collated for speed of insertion.||Drywall screws||N/A|
|Floorboards||Twin thread for fast start, single thread for hold, countersunk head||Ease of start up. High pull-out retention. Minimal splitting Flush finish||Brass crosshead, countersunk screws||N/A|
|Decking||Sharp point, single thread with shank and countersunk head||Pierce surface, strength in position. Minimise jacking up and splitting. Flush finish.||Decking screws||Deckings screws|
|Roofing Sheet||Roofing screws||Self-drilling and self-tapping with rubber bonded washer for weather proofing||Roofing hook bolts or mushroom bolts or Aluminium nails||Roofing hook bolts or mushroom bolts or Aluminium nail|
|Fencing and Garden Furniture Marine||Rust resistant – Easy to drive||Resistant to corrosion. Speedy insertion||Ulti Mate wood screws||Ulti Mate wood screws|
Never try to use the wrong screw. Not only will it be hard to put in but it may not hold for the job you want to do. For fixing methods to various surfaces, go back to the projects section. Fixing to masonry is a popular task as is fixing items to plasterboard.