Types of Screw for Different Uses - What Type of Screw Should be Used for What Kind of Job or Material Being Screwed

Summary: Different materials need to be screwed with different types of screw. This project helps you make sure that you select the right screw for the job that you are doing. Uses this comprehensive table to match the job you're doing with the types of you should be using. We explain the different types of screws available, where you should use them, including internally or externally, and why so that you can understand the importance of using the right screw. Knowing where to use different types of screws is half the battle and will ensure they hold fast.

Don't want to do this job yourself? Let us help you find a tradesman local to you

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.

Wood screws are great for holding wood but you should not use them for metal. Decking screws are for decking, but not for MDF. Different types of screw should be used internally and externally in many cases. If you understand why, it is much easier to know what screw you should choose.

Another area of confusion is which size screw that you should use, and how to work out this size when the sizes are quoted in metric and imperial measurements! This is a whole different story so please take a look at our table of screw sizes here.

Screw sizes vary and generally the larger the number the bigger they are. For example a number 6 screw is much smaller than a number 12.

Additonally, there are many types of fixing for all types of material and circumstances so make sure you get the right one to go with the correct type of screw to make the job as easy as possible.

It is usually much easier to insert screws when you have drilled a pilot hole. This prevents them from binding. Drilling the correct size pilot holes will certainly make screwing down much easier and help to avoid your timber splitting and also countersinking the heads makes for a much neater job so checkout our countersinking and pilot holes project here also.

Selecting the Right Screw for the Material

Use the tables below to work out which screw you should be using for the material (or substrate) that you are working with. If you understand the reason why, this will make it more logical and easier to understand. We Hope!

Hardwood

Material / Substrate Type of screw Reason Internal External
Hardwood Twin thread Ease of start up and driving Zinc plated twinthread Brass or Black Jappaned screws
General purpose twin thread screw

Internal use Zinc Plate Twin Thread Screw (ZP TT) - Available in our store here

Brass general purpose countersunk screw

External use Brass Twin Thread Screw - Available in our store here

Soft Wood

Material / Substrate Type of screw Reason Internal External
Soft Wood Single thread Strength in position – High pull-out retention Zinc plated countersunk Brass or Black Jappaned screws
Single thread countersunk screw

Internal use Single Thread Counter Sunk Zinc Plated Screws (ST ZYP Countersunk) - Available in our store here

Single thread japanned screw

External use Single Thread Japanned Screws - Available in our store here

Chipboard

Material / Substrate Type of screw Reason Internal External
Chipboard Single thread High pull-out retention Chipboard Countersunk screws Do not use chipboard outside unless covered
Countersunk chipboard screw

Internal use Countersunk Zinc Plated Screws for Chipboard (CSK ZYP) - Available in our store here

MDF

Material / Substrate Type of screw Reason Internal External
MDF Single thread with twin thread start – makes the first “biting” twist easy Twin thread allows ease of start up and single thread provides high pull-out retention MDF of Carcass Countersunk screws Do not use MDF outside unless covered
MDF screw

Internal use MDF screw - Available from Amazon here

Single thread japanned screw

Internal use alternate suggestion of Carcass screws - Available in our store here

Wood – Traditional Finish

Material / Substrate Type of screw Reason Internal External
Wood – Traditional finish Single thread Traditional finish required to product Zinc or brass roundhead screws Brass ditto
Round head zinc plated screw

Internal use Round head Zinc Plates Screws - Available in our store here

Slotted brass screw

External use Traditional Slotted Brass Screws - Available in our store here

Masonry

Material / Substrate Type of screw Reason Internal External
Masonry Single thread – Self tapping case hardened with groove in thread to allow dust to escape Single thread for hold and drive to grind into masonry Concrete and Masonry self tapping screws Frame screws and hammer fixings
Concrete frame screw

Internal use Concrete Frame Screw - Available in our store here

Frame or hammer fixing

External use Frame Fixings and Hammer Fixings - Available in our store here

Metal

Material / Substrate Type of screw Reason Internal External
Metal Self tapper Cut their own thread into metal Self Tapping screws Stainless steel self tappers, ideally or Zinc Plated self tappers
Self tapping countersunk screw

Self tapping Zinc Plated Screws (ZP) - Available in our store here

Plasterboard

Material / Substrate Type of screw Reason Internal External
Plasterboard Drywall screws Sharp piercing point with twin thread and bugle head for flush finish. Can be collated for speed of insertion Drywall screws Not Used Externally
Drywall screw for plasterboard

Internal use Drywall Screws - Available in our store here

Floorboards

Material / Substrate Type of screw Reason Internal External
Floorboards Twin thread on the first few mm for fast start, single thread for hold, countersunk head Ease of start up and high pull-out retention with minimal splitting and a flush finish Brass crosshead, countersunk screws Not Used Externally
Slotted brass floorboard screw

Internal use Traditional Slotted Brass Screws - Available in our store here

Decking

Material / Substrate Type of screw Reason Internal External
Decking Sharp point, single thread with shank and countersunk head Pierce surface, strength in position with minimise jacking up and splitting and a flush finish Decking screws Deckings screws
Pozi drive decking screw

External use Decking screws - Available in our store here

Roofing Sheet

Material / Substrate Type of screw Reason Internal External
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
Roofing screws

External use Roofing Screws - Available in our store here

Fencing, Garden Furniture and Marine

Material / Substrate Type of screw Reason Internal External
Garden and marine Rust resistant – Easy to drive Resistant to corrosion and speedy insertion Ulti Mate wood screws Ulti Mate wood screws
Ulti Mate wood screws for external use

External use Ulti Mate wood screws - Available here from Amazon

Using the Wrong Screw Type

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 and is worth reading up about in our project, as is fixing items to plasterboard, as this may require a little more strengthening behind the plaster board to get a secure fixing particularly if your are fixing something heavy.

Abbreviations Commonly Used to Describe Screws

There are a number of abbreviations that are used to describe the type of screw. You can use these to help your search; just put the abbreviation into our shop search bar (in our online store here) and you should get the results you are looking for.

  • ST: Self Tapping; Allows screwing into the material without having to drill a pilot hole, although one can be used if necessary
  • CSK: Countersunk
  • SCT: Single Thread, Course Thread
  • TT: Twin thread
  • TFT: Twin Fine Thread
  • ZP: Zinc Plated; for corrosion protection
  • ZYP: Zinc and Yellow Passivated; a further passivation layer is applied to the zinc coating to provide even greater corrosion protection

Selecting the Right Size Screw

As mentioned above, we do have a project all about the sizes of screws, and how to convert the metric to imperial sizes. This is very helpful, so please have a read, but this project would not be complete without a word on how to select the right size screw for the work that you are doing.

There are no hard and fast rules for choosing the right screw length for the job that you are working on but we do have a few guidelines to follow.

The screw needs to be long and strong enough to hold the parts that you are fixing together, without going right through and sticking out the other side. Its length will be determined by the forces. The more force the longer the screw that will be required to make a sound fixing. It also needs to be long enough to get a secure fixing into the material that is being fixed too.

The direction of the forces that will be applied to the fixing need to be considered. If the force is lateral, or pushing along the joint of the two materials being fixed, then a thicker screw should be used.

When using thicker screws or when fixing brittle materials including some hardwoods, the material can be prone to splitting. Obviously this is not a good thing, so it is wise to drill a pilot hole before screwing in your screw – find out about how to drill pilot holes in the project mentioned at the top of this page.

Consider also, the number of screws that you use. Use as many as you can where warranted, particularly if you are limited, say in the length of screw that you can use. The extra ones added will provide a stronger fixing to make up for the weakness of each individual fixing.

Different Kinds of Screws and Their Parts

We do not cover the different parts of screws in this project, as we are focusing on helping select the right type of screw for the job of materials that you are working with. To find out about the different parts of screw and the different head and thread types see our project here.

Here we have focused exclusively on screw fixings, but there are a great deal of other fixing that are commonly used. These include using screws with plugs, such as rawl plugs. For more information about the options and which is the right choice of fixing, read our Fixings Project mentioned above.

The topic of the different types of screw and how they should be used is a complex one, so we want to keep it simple. The table above will provide you all the information you need to select the type of screw that you need for the material that you are working with. With this information, you will always be able to choose the right one for the work you're doing.

Don't fancy doing this project yourself? We work with Checkatrade to ensure that we recommend only reliable and trustworthy tradesmen.

All project content written and produced by

Project Feedback