We all love a good screw, but did you know there are a whopping 34 different types? Each has been carefully designed for use with different materials and finishes. Using the wrong one for your project could be a disaster. In other words, you get screwed.
Find out which screw is right for your project by learning about the different types. Discover every bolt in this month’s article.
Types of screws
These are the different types of screws:
- Wood Screws
- Machine Screws
- Thread Cutting Machine Screws
- Sheet Metal Screws
- Self-Drilling Screws
- Hex Bolts
- Carriage Bolts
- Lag Bolts
- Socket Screws
- Set Screws
- Mating Screws
- Flat Screws
- Raised Screw
- Bugle screws
- Binding Screws
- Domed Screw
- Flange Screw
- Truss Screw
- Phillips screw
- Eye bolts
- Shoulder bolts
- Elevator bolts
- Sex bolts
- Hanger bolts
- Decking screws
- Thread Rolling Screw
- Weld screws
- Raised or slotted cheese screws
- Fillister head screws
- Drywall screws
- Self-tapping screws
- Framing screws
- Tamper resistant screws
To give you a better idea of the different types of screws in detail, I’ve compiled 34 types of screws with highlights of their main uses and features.
1. Wood Screws
Wood screws consist of a threaded shaft and are used to connect wood to wood. These types of screws have different thread times and are available in a range of different heads. The most common wood screw heads, however, are flat and round heads.
Advantages of wood screws:
- The round-head varieties are ideal for attaching thin materials to wood
- The flat-head screws are highly useful for securing hinges
- Regular wood screws are often made from stainless steel or brass to make them more durable
What they’re used for: all types of wood.
2. Machine Screws
Machine screws are used to hold parts of machines in all kinds of industries, such as electronics, engineering, and manufacturing equipment. These screws are specifically designed to fasten to a tapped hole on a surface with the help of a nut.
Their blunt ends are used to attach metal parts together. Machine screws can be found in almost every material including nylon, brass, stainless steel, and carbon steel.
What they’re used for: fastening metal parts together
3. Thread Cutting Machine Screws
Thread-cutting machine screws consist of sharp edges so it’s important for the depth of the hole to be a little longer than the screw. This will avoid the material from getting trapped inside the device. The role of thread-cutting screws is to minimize the creation of internal device stresses, thus making them ideal for extremely stiff materials.
This is in contrast to a thread forming screw, whose edge does not have any cutting, which makes it difficult in materials with low compressive strength force. But this forms a tight bit between the thread-forming screw and the material.
What they’re used for: most often used with wood and metal.
4. Sheet Metal Screws
Sheet metal screws can fasten or connect two pieces of sheet metal together to tubing or other metal types. There are different types of sheet metal screw heads available including flat, hex, and round. These slotted screws are made from pure steel with a weather-proof coating of stainless steel or aluminum. They are most commonly used in the welding industry.
What they’re used for: sheet metal
5. Self-Drilling Screws
Self-drilling screws come in different lengths of drill tips. The highest number is equal to a longer drill tip. You also have the option of choosing different point sizes based on their diameter.
Bear in mind that the material’s thickness will affect the length requirements of the point. Self-drilling screws also have a variety of uses and types and are mainly used for fastening or joining sheet metal or steel to other metals.
What they’re used for: quick drilling into metal or wood.
6. Hex Bolts
Hex cap screws are large-sized bolts with a hexagonal head hence their name! They are used to attach wood or metal to wood. Hex screws consist of tiny steel threads that make them ideal for interior home improvement projects or stainless-steel exterior tasks. These screws also feature a flat washer under the screw head and provide precise applications.
What they’re used for: fastening wood to wood or metal to wood.
7. Carriage Bolts
Carriage bolts are specifically used in woodworking projects to fasten metal to wood. These bolts have a domed head that prevents loosening. The large head shape of carriage bolts also prevents them from getting pulled through a wooden construction.
Aside from being intended for use in woodworking projects, carriage bolts are just as suitable for metal applications thanks to their machine screw thread. Having said that, carriage bolts are not compatible with drill adaptors so installing them in a metal can be rather difficult if not impossible.
What they’re used for: fastening metal to metal or metal to wood.
8. Lag Bolts
Lag screws typically consist of a hexagonal head and are designed for high-impact applications. The most common places you can find these screws include decks and wood-retaining sidewalls.
Lag bolts are extremely strong, durable, and long-lasting. They are mostly made of high-carbon steel for the core with an outer galvanized zinc. The galvanized zinc material protects them from rust and corrosion. What’s more, moisture and air can’t penetrate into lag screws, thus making them rust-resistant.
What they’re used for: connecting heavy lumber or other heavy materials that are bearing an intense load.
9. Socket Screws
Socket-head screws are perfect for when you need a fastener to sit below your material’s surface. These types of screws are highly strong and reliable wherever a joint is required. They are also exceptionally resistant to corrosion. But aside from their sturdiness, they ensure an attractive and quality finish.
Main features and benefits of socket countersunk screws:
- Available in different thread sizes
- Highly resistant against corrosion
- Made of stainless steel
- Head height is same as shank diameter
What they’re used for: fasting machine parts.
10. Set Screws
Set screws are used to fasten an object to or against another object. For example, gear or pulley can be secured to a shaft using a set screw. These screws are fully threaded without a head sticking out, and there are many different shapes and sizes available.
The most common variations include:
- Flat set screws: these screws adjust into the surface of the application without damaging it by aligning against the ground
- Knurled cup screws: they feature a locking action to stop the screw from loosening in high-vibration applications
- Cup point screws: these are the most common types of set screws that permanently hold components on hard or soft surfaces
What they’re used for: to secure an object within another object.
11. Mating Screws
A companion for sex screws. They have a plan shaft and a threaded portion, which is received by the internal threaded part of the sex screw.
What they’re used for: bolting applications where a head is desired on both sides of the joint.
12. Flat Screws
Flat screw heads sit completely flush with a surface, leaving no head exposed. You have to countersink these types of screws.
The advantage of flat screws is that you don’t have to worry about the screw sticking out of the surface and other things snagging on it.
You also don’t see the screw head when using a screw cover.
13. Raised Screw
Raised heads, sometimes known as oval heads, have a similar angle to flat screws, but have more of a dome-shaped head. You will also need to countersink these screws to accommodate the angle.
Unlike a flat screw, the head of a raised screw protrudes slightly from the surface. This shape doesn’t necessarily help the driving power of the screw, but is more for decoration.
14. Bugle screws
Bugle heads are primarily used on screws made for plasterboard and drywall.
This shape is similar to a flat screw head, except instead of an angle below the surface of the head, you see a curved shape that can reduce damage to a surface.
Bugle screws are self-drilling so you don’t need to pre-drill prior to use, and their unique shape allows them to spread the stress over a wider surface area than flat head screws.
15. Binding Screws
Binding screws, also known as book screws or book binding screws, have numerous uses including for use with color charts, swatch books, catalogues, fabric swatch books and albums. By using them with grommets or hangers, you can hang the pattern book neatly and conveniently.
We supply both metal and plastic screws. The metal tubes and metal screws are supplied separately. You have the choice between a screw with an extension, a hammer head screw or our patented hammer head screw with an extension. The plastic binding screws are supplied in standard combinations as a set consisting of a tube and a screw. We can also supply plastic binding screws with holes.
The advantage of binding screws is that they are not permanent and therefore you can update your catalogue. You can also use them in combination with a variety of accessories such as extension pieces, binding screw sample strips, spacers, hanging loops, top caps and washers.
16. Domed Screw
Dome Screws are used to secure the top straps of a helmet in place of a buckle. Low Profile, Stainless Steel, Won’t gouge or cut opponent’s helmet.
Dome Head Screws have an oversized “truss” head style with an undercut bottom and a low height rounded dome top. Choose between Phillips and Slotted drives as well as machine and sheet metal threading.
17. Flange Screw
A flange is typically a small protruding flat rim, collar, or rib on a bolt for reinforcement or attachment. Flange Bolts are extremely safe when used in specific applications.
These screws distribute pressure where the screw meets the surface without taking up the space required for a washer. This eliminates the need for a separate washing machine, saving space and money.
A flange head can be any head shape (except countersunk shapes) with the addition of an integral flange at the base of the head. This eliminates the need for a washer.
The flange head lies flat on the surface of the material into which it is screwed. It is commonly used in the furniture industry to attach hard fiberboard panels to the rear of cabinets and shelves. The flat, washer-like head of the screw saves space and enlarges the contact surface on the fiberboard.
18. Truss Screw
Truss-head screws are threaded fasteners with a mushroom-shaped head. They have a broad and slightly rounded head resembling a mushroom. With their mushroom-shaped head, truss-head screws protrude from the workpieces in which they are installed. They do not sit flush with workpieces. After a truss head screw is fully driven into a workpiece, the head will stick out.
You’ll usually need truss heads when working with sheet metal and other projects that require large holes because the wide head prevents the truss screw from going through the hole.
19. Phillips screw
The head of Phillips screws is designed in such a way that the screwdriver head can slip out if excessive force is applied. The specific design of the head allowed the Phillips head screw to handle higher torque much better than other fasteners.
Also, because they allowed for tighter attachment, they immediately found their place on assembly lines, and it wasn’t long before these screws were being used for a variety of applications.
The benefits of such features can be seen in the famous Model T, the first truly affordable Ford vehicle that opened the road to the general American middle class. In fact, the Model T is considered one of the world’s most influential cars of the 20th century.
20. Eye bolts
Eyebolts are perhaps the most commonly used screws by both homeowners and material handling specialists. In fact, you are bound to have come across these bolts in your local hardware store. An eye bolt consists of a threaded shank and a ring at one end. These bolts are designed to lift objects by passing a rope or wire through their eye.
Different uses for eye bolts:
- In industrial settings, the larger-sized eye bolts are used for lifting and tensioning.
- In homes, they are used for hanging decorations or plants on walls
- In welding industries, stainless steel eye bolts are ideal for harsh weather conditions as they can be used for heavy-duty outdoor welding applications
What they’re used for: attaching a rope, chain or cable.
J-bolts are J-shaped screws that are threaded on their flat side. These bolts are often used in construction applications like connecting walls to stone or concrete foundations. The curved end of J-bolts is for extra support and can be placed in concrete for use as anchor fasteners. The long end of these screws come in different lengths and they can be threaded using a hook, hence the end result will look like a J.
What they’re used for: as a fastener for construction projects.
U-bolts are industrial fasteners that are U-shaped with two threaded legs or arms to provide a bent base. These threaded legs or arms are designed to be used with screws and washers, but they can also be used with a crosspiece for a more secure result. A U-bolt can be inserted in pre-drilled or punched holes and is most commonly used in plumbing, industrial, and construction projects.
What they’re used for: fastening pipes and as anchors for foundations and roofs.
23. Shoulder bolts
Shoulder bolts are in the same category as machine screws. They comprise the head, shoulder, and threading, with the head part having the largest diameter. These bolts are especially known for their unique features and versatility.
They are used in a variety of industries, from automotive to wooden furniture making. They are also useful for pulleys and linkages. Shoulder bolts are often found in exterior wooden structures.
What they’re used for: rotating items such as bearings and bushings.
24. Elevator bolts
Elevator bolts enjoy a wide variety of application usage. For example, they can secure any type of flooring, level wooden furniture legs, and you can even find these bolts on skateboards and snowmobiles. The threads are designed as standard right-hand and you can choose from long to short lengths that are fully threaded.
The length measuring starts from the top of the head all the way to the end of the threaded fastener. The head of an elevator bolt can be countersunk flat, shallow conical, square neck under the head, or a unified thread to name some of the few.
What they’re used for: in conveyor belts, elevators and similar mechanical systems that raise things up and down.
25. Sex bolts
Sex bolts are in the same category as mating screws. They are also known as inter crews, barrel nuts, partition screws, panel fasteners, binding posts, Chicago screws, and architectural sex bolts.
A sex bolt is a type of nut or fastener with a barrel-shaped flange and pointed boss that’s internally threaded. This bolt with its accompanying machine screw sits on either side of a material or surface that requires securing. These types of nuts are chosen for their low-profile and built-in slot features, which aid in tightening the screw into the surface.
What they’re used for: bolting applications where a head is desired on both sides of the joint.
26. Hanger bolts
Hanger bolts are headless screws used mainly with wood applications to provide an additional external thread or to create an internal fastening joint. One side of the hanger bolt thread, together with a self-tapping lag screw, grips into the wood, while the other side of the bolt has machine screw threads for a nut.
Because of such features, hanger bolts are extremely popular in storm shutter applications, and they are commonly used in furniture making, framing, and flooring joints.
What they’re used for: suspending objects from or attaching items to wood.
27. Decking screws
Decking screws are made of stainless steel or carbon steel and specially designed to attach wooden or composite boards to metal or wood. These screws come in various widths and lengths and are the perfect solution for fastening decking boards to frames.
Advantages of decking screws:
- Used for fastening wood or composite deck boards to frames, thus making them ideal for the shipbuilding industry.
- Widely used in exterior fence-building applications.
- Can fasten wooden chairs and simple decking structures.
- No pre-drilled holes are required.
28. Thread-rolling screws
Instead of cutting threads into the material, the thread-rolling screws create threads by exerting pressure against the material’s walls. These screws are mainly used for softer materials, such as wood, plastic, or nylon.
Their double lead thread style minimizes torque and enhances pullout power. This prevents the material from cracking or damage. There are some thread-rolling screws that also feature widely-spaced threads that make them easier to insert into pre-drilled holes.
29. Weld screws
Weld screws are welded to an aluminum or metal surface to create a shaft for the components that are to be fitted or fastened. This can be done using a washer or nut. The tabs of weld screws extend from the head in order to allow welding without using a hole. The welding stud is then fastened to a metal piece. This stud is located on the metal’s base.
These types of screws are most frequently used in the automotive, industrial, marine, construction, cookware, and aerospace industries.
30. Raised or slotted cheese screws
Slotted cheese head screws are made from stainless steel and are designed with a round, raised head. The cheese head’s height is almost equal to half the head’s diameter. These screws are highly popular in industrial, electrical, telecommunication, and automotive lighting applications due to the fact that they are extremely rust and corrosion-resistant and can be used in underwater projects.
31. Fillister head screws
Fillister head screws are slotted head machine fasteners with a large over-sized head that can be used for attaching metal or wood to metal. Also referred to as cheese head screws, the fillister head fasteners are similar to pan head machine screws but with a bigger side height. The head of these screws is mainly preferred for counterbored holes.
32. Drywall screws
Drywall screws are standard fasteners for securing partial or full sheets of drywall to wall or ceiling joists. There are two types of drywall screws available. These are:
Coarse: this type of drywall screw is mostly used for wood studs. The widely arranged threads are effective in gripping the wood. The drywall screw also features an extra sharp tip and a phosphate finish.
Fine: this type of drywall screw is self-threading, thus making it perfect for metal studs. The fine drywall screws have double threads for easier and more practical self-starting.
33. Self-tapping screws
Self-tapping fasteners tap their own thread, hence the name. To use them, you need to drill a hole slightly smaller than the screw’s diameter. Once you’ve drilled a pilot hole into a soft material like wood, you can then drive the self-tapping screw in. The threads of the screw will dig into the wood and keep it secure.
Self-tapping screws can, in fact, be used in all kinds of materials like metal and brick, not just wood. For harder surfaces, it may be best to choose the self-tapping screws that have pointed tips on their thread in order to cut into the material. However, not all self-tapping screws have pointy tips; some will be flat or blunt so make sure you choose the right one for your specific application.
34. Framing screws
Framing screws are multi-use fasteners for sheet metal, wood, laminate, composite decking, and cement fiberboard applications. These screws are designed to countersink into many different materials, from hardwood flooring to brittle composite. This can be achieved by the cutting teeth of the screws under head as well as the six cutting pockets.
Framing screws work very similarly to circular saw blades as they prevent the sawdust from getting to the edge of the screw hole. The hole can then be sealed off without damaging the surface of the material.
35. Tamper resistant screws
Tamper-proof screws are suitable for use in buildings or areas that are accessible by the public to prevent or deter vandalism. This security screw type can be distinguished by its unconventional drive, which makes tampering or disassembly more difficult, if not impossible. These tamper-proof screws are mainly used for securing materials, such as car license plates, gutters, and grill bars in prisons.