Wherever you see a right angle or a moving component, there’s a good chance a screw is tucked away somewhere inside it.
As well as being central to many DIY projects, screws come in a bewildering array of sizes, shapes and designs.
Below, we’ve listed the 12 different types of screws you need to know. However, before discussing the differences between double-ended screws and eye bolts, we must consider the anatomy of a screw.
Keep the Tip
There are five main components to any screw:
The tip is the first point of the screw that makes contact with whatever material you’re drilling/hammering/screwing it into.
Everything between the tip and the head (which we’ll get to in a moment) is the shank. Shanks can be smooth in parts (known as non-threaded), but they’re mostly threaded.
The thread is the tapered or spiral part of a screw, with visible ridges rising to a defined crest. It gives the screw much better adhesion than a nail, but it might not cover the entire length of the shank.
Depending on how steeply they’re angled, some threads have varying angles, and spacing can vary, too.
The head is usually a larger diameter than the shank to prevent it from being over-inserted.
A countersunk thread gradually narrows towards the shank and is designed to fit flush with an exposed surface.
One or more recesses cut into the screw head, enabling a screwdriver or other handheld tool to rotate the screw into its final position (and remove it if needed).
These five components lend themselves to an immense degree of variance. Experts disagree on how many different types of screws exist because there are so many variations on general themes. We’ve kept things simple by condensing our list to a dozen different types of screws.
There might be several screws which would work equally well for a particular DIY job. With one or two notable exceptions, screws are remarkably interchangeable. For example, the only difference between hex and lag bolts is that the latter has a tapered tip.
In outlining the different types of screws below, we will briefly mention the materials. However, it’s often a matter of personal preference whether a screw is made from brass, steel, titanium or other materials.
Copper alloys are common because they’re durable and have a high load capacity, while plastic screws are ideal near water.
Pro Tip: Because they’re conductive, aluminium screws might benefit from being driven by a VDE screwdriver.
If the screws are exposed, and aesthetics are essential, electroplated chrome or zinc-coated screws look good, while black oxide coatings add visual drama.
Some screws are manufactured from materials such as steel, while others use a variety of consumer-friendly base metals, alloys or coatings.
Driving up Standards
There are many different types of drive recesses on a screw. Below are some of the most common types which will affect your choice of screwdriver/drill bit:
- Slotted. A single groove through the centre of the head accommodates various screwdriver bit sizes. The head can be flat or bulbous (oval).
- Phillips. The iconic deep plus-shape is set into either a flat or oval head. A small area surrounding the plus may be slightly recessed (pan head, which recurs on several other screw types).
- Star drive. Also known as Torx, this is a star-of-David-shaped inset in the centre of the head. Again, heads can be flat, round, or pan (most common).
- Combo head. Effectively a Phillips, but with one of its two cross-beams extended into a slotted style.
- Hex washer. A hexagonal head that a spanner can turn. Often accompanied by a slotted groove.
- Square head. A rarely-seen variant designed for tightening and loosening using a grip wrench.
- Carriage head. A smooth, flat circular head with a small countersink immediately behind it. They’re often used to secure metal to either timber or more metal.
- Capped. A screw head that you can sometimes hide underneath a cap. For instance, a bathroom mirror might come with screws whose chrome caps tie into the aesthetic of the mirror.
12 Different Types of Screws – Runners and Riders
Let’s start with arguably the most common type of screw used by DIY enthusiasts and one you’ll already be comfortable deploying…
1. Wood screws
Steel or brass wood screws have a tapered body and pointed tip to create their own thread. Heads can be oval but are usually round and flat.
Length is often the determining factor in choosing wood screws, depending on how thick each piece of timber is and the bite you need to reach adjoining materials.
2. Drywall screws
There are two sub-categories here:
- W-type Screws
Use these coarsely threaded screws for attaching drywall to wood.
- S-type Screws
Use these more finely threaded screws for attaching metal studs to drywall.
S-types are often notable for their self-drilling tip, designed to slice through drywall easily and reduce the need for other tools.
There are as many different types of drywall screws as wood screws. There are also numerous coatings, from zinc to ceramic.
If the plasterboard is thin and you can’t find a supporting timber baton to screw into, drywall screws may need to be used with anchors or rawlplugs to ensure you distribute the weight evenly. We’ve recently published a guide to plasterboard fixings.
3. MDF screws
Medium density fibreboard is so ubiquitous that screw manufacturers developed a new class for it.
You’ll come across MDF screws with their distinctive central threads and star drive in most flat-pack furniture boxes.
If holes aren’t pre-drilled, the ultra-tough materials used to manufacture MDF screws should splinter through even the toughest chipboard.
4. Decking screws
Uniquely among this list, decking screws are intended to sit slightly below the surface because an exposed screw head on timber decking could be dangerous, even if it’s painted over.
Decking screws often have a star drive, with coarse threads and a smooth top section, and they’re made of rust-resistant steel to withstand rain and snow.
5. Double-ended screws
Also known as ‘wood-screw threaded studs’ or ‘dowel screws’, double-ended screws resemble a dowel more than a conventional screw.
These screws have threads at both ends with a smooth barrel in the centre and are commonly used to join two pieces of material (often timber) where no right angles are involved.
Note: a set screw is effectively a single-ended screw intended for being buried out of sight.
6. Mirror screws
If you were paying attention earlier, you’d remember us talking about capped screws. Mirror screws are the most common example and come in two parts – the screw and the cover/cap.
The slotted countersunk head includes a central threaded hole into which you can screw a cover/cap. The cover/cap provides a pleasing finish and is often chrome, whereas the screw is steel or aluminium.
7. Security screws
These rather unappealing-looking screws prevent tampering.
Security screws typically come with specialist screwdriver bits for insertion and removal, which wouldn’t necessarily be available to the layperson with a standard screwdriver set.
Their round heads are impervious to spanners or standard bits, so if you use security screws, ensure you keep the associated bits safe.
8. Masonry screws
We’re plunging into specialist territory here since masonry screws (also known as anchor screws) are for concrete use only.
If you fit wooden floor plates to a concrete sub-base, these screws are your weapon of choice.
Masonry screws are relatively long, with serrated threads and hex heads. To make your life easier, use a powerful corded hammer drill to drive their sharp tips and solid construction into masonry walls.
9. Self-tapping screws
There are limited circumstances where you’d want to insert screws without pre-drilling, but self-tapping screws are on standby for those occasions.
As well as the usual thread, they have an elongated tip resembling freshly dispensed ice cream, boring its way through a surface before the thread bites.
Pro Tip: Be careful not to over-tighten self-tapping screws as they’re prone to stripping on removal.
10. Sheet metal screws
Available with various flat, hex and round heads, sheet metal screws are almost always steel-based with a weather-resistant coating over the top.
Welders use sheet metal screws because their fully threaded shanks and sharp-pointed tips remain securely in situ. You can also use them to attach anything from plywood to plastic.
11. Eye bolts
These industrial-standard screws have a threaded shank and a ring or securing mechanism at one end.
You will typically use eye bolts to support the weight of an object attached to a rope/wire fed through the eye.
They’re almost indestructible when made from stainless steel and properly inserted into a concrete surface. U-bolts, J-bolts and eye lags are variations on this anchoring theme.
12. Sex bolts
Stop sniggering at the back. Sex bolts maintain a strong bond between a screw and a matching threaded tube.
Sex bolts are part of a niche market, home to products like the one-way tamperproof sex bolt, which is helpful in scenarios where you need an accessible head at both ends of the connection.
Final Thoughts – Different Types of Screws
It’s surprising how diverse screw designs are, yet you’ll probably recognise our main categories from previous DIY jobs and the contents of your tool bag.
Choosing the correct type of screw is often a matter of common sense – it needs to be waterproof for fencing, plastic for positioning near water, and so forth.
To learn more about screws, check out our simple guide to picking the correct screw size.
What is a screw?
Technical definitions vary, but we’d generally describe it as a central shaft surrounded by an angled corkscrew plane.
Screws have a wedge-shaped head that features either a bolt or a groove, into which you can snugly fit specific bits to drive the screw’s rotation.
What’s the difference between a screw and a bolt?
As you insert a screw, its threads cut a helical groove into the material to embed it and prevent it from being withdrawn accidentally.
How can I obtain a suitable bit to tighten a particular screw?
The more extensive your screwdriver bit set or drill bit collection, the more likely you will have a bit that will match a particular screw. Security screws should come with compatible fittings, so keeping them safe is vital.