Types of Fasteners (Screws, Rivets, and Washers) - Engineering Choice (2023)

Fasteners play a critical role in the construction of all sorts of everyday objects. If you’ve done any DIY projects, you’ve likely used fasteners to help get the job done. At All Points Fasteners, we’re passionate about the role quality fasteners can play for handy homeowners and professionals alike. Let’s take a moment to define fasteners and overview some of the different types, as well as the various uses for them.

What Is a Fastener?

Let’s start by defining what a fastener is. The term fasteners encompass a fairly broad category of tools, such as screws, nuts, and bolts, that share a common purpose: to mechanically hold objects together. Of course, things like glue can fulfill this function, but glue is not a type of fastener. Therefore, we need to add to our definition. Hardware fasteners mechanically hold objects together.

Typically, fasteners form a non-permanent joint. In other words, when you use a fastener to connect two components, you can remove it, and the separate pieces should come apart without suffering any damage.

The same wouldn’t be the case with a welded joint, for instance. The one exception to this rule is rivets, which fall under the category of fasteners but create permanent joints.

Though most fasteners form a non-permanent joint, this does not mean you only use fasteners when you want to be able to take something apart, and it doesn’t mean the joint is weak by any means.

Fasteners can reliably hold together objects that can experience a great degree of stress. That means they’re a great choice for permanent and non-permanent joints alike, providing versatility for the type of project you want to use them for.

The Most Common Types of Fasteners

Mechanical fasteners come in different types. Each of those types also has many subtypes that you can choose from. Among the different types of fasteners, here are the most common ones:

• Bolts: These types of fasteners help to hold two unthreaded parts together. They can be called the most common types of fasteners.
• Screws: For many people, when they think of fasteners, screws are the first thing to come to mind. Screw fasteners are one of the most versatile types of fasteners out there. Their threaded shafts give them durable holding power, and unlike a bolt, they don’t require anything to hold them in place. Typically, you use a drill to make a pilot hole in a material and then use a screwdriver to drive the screw in place. Screws come in a wide variety of types and sizes.
• Nuts: A nut comes with an internal thread that works with a bolt to hold components together.
• Washers: They are small, circular discs shaped like an annulus. They also work together with nuts and bolts and serve important fastening functions.
• Nails: Nails have been used since ancient times, and they are still an everyday household item. You can easily spot the difference between a screw and a nail because a nail doesn’t have threading. While a nail doesn’t provide the same holding power a screw does, it has greater shear strength, making it the better choice for some applications.
• Rivets: These are permanent fasteners that help secure several different types of components.
• Anchors: Anchors get their name because they serve a similar function to a boat’s anchor, which embeds itself in the seabed to keep a ship from moving. Generally, people use these fasteners to connect something to a material like drywall or concrete. They embed themselves in the material and hold the object you’re affixing in place.

Types of Screws

1. Deck Screws

Longer screws are used for fastening down deck boards. Deck screws feature a type 17 point (notched point at the tip) to aid in chip removal during thread cutting which allows for an easy installation in wood and composite deck materials. A bugle head and square drive help to eliminate the stripping effect sometimes experienced with other types of drives.

2. Hex Lag Screws

Lag screws, also called lag bolts, are large wood screws. The head is an external hex and is driven with a wrench. Used for lag together lumber for framing, machinery to wood floors, and other heavy-duty applications.

3. Self-Drilling Screws

Self-drilling screws have a sheet metal thread with a self-driller cutting (TEK) point to pierce through 20-to-14-gauge metals. The higher the TEK number, the larger the drill point to pierce heavier gauge metals.

4. Sheet Metal Screws

Sheet metal screws (SMS) have sharp cutting threads that are cut into sheet metal, plastic, or wood. They have a fully threaded shank and sometimes have a notched point at the tip to aid in chip removal during thread cutting.

5. Wood Screws

Wood screws are partially threaded with large cutting threads and a smooth shank. They are designed to slide through the top piece of wood and tightly pull all boards together.

6. Concrete screw

Stainless or carbon steel and used for fastening materials to concrete.

7. Masonry screw

Often have a blue coating and are inserted to a pilot hole in masonry.

8. Double-ended (dowel) screw

Have two pointed ends and no head. Often used for making hidden joints between two pieces of timber.

9. Drive screw

Smooth, round, or mushroom-headed with a reduced diameter shank.

10. Drywall screw

Often coated with black phosphate and designed with a bugle head. Used to attach drywall to timber or metal studs.

11. Eyebolt

A looped head is designed to be used as an attachment point. Also used for attaching wires across building surfaces.

12. Lag screw/bolt

A heavy-duty fastener.

13. Chipboard screw

Often wax-coated and used for fastening down chipboard flooring.

14. Mirror screw

Designed with a decorative dome or another cover to conceal the head.

15. Twinfast screw

Designed with two threads that enable it to drive twice as fast.

16. Security head screw

Designed with a head that is impossible to reverse, making it suitable for security applications.

Types of Rivets

1. POP Rivets (Open-End)

POP Rivets, also known as blind rivets, are used to connect two pieces of material in a quick, efficient way. POP Rivets are tubular, comprised of a hat and mandrel; the length of the mandrel is snapped off when installed.

2. Closed-End POP Rivets (Sealed)

Closed-End Rivets differ from a standard blind pop rivet in that they feature a closed-end which creates a watertight seal.

3. Large Flange POP Rivets

The large flange also called Oversize, pop rivets have a larger washer on the hat than standard POP Rivets. Also known as blind rivets, they are used to connect two pieces of material in a quick, efficient way.

Large flange POP Rivets are tubular, comprised of a hat and mandrel; the length of the mandrel is snapped off when installed.

4. Countersunk POP Rivets

Countersunk, also called Flat, POP Rivets, are used to connect two pieces of material in a quick, efficient way. The hat of the rivet is almost inverted, with a 120-degree countersink in the integrated washer.

POP Rivets are tubular, comprised of a hat and mandrel; the length of the mandrel is snapped off when installed.

5. Colored Rivets

Colored rivets are open-end pop rivets. Colored rivets have a hat that has been painted Wither brown, black, or white. These colors are used either to hide rivets and create a finished look or to make them extra visual by using the opposing color from the installation material.

6. Multi-Grip Rivets

Multi-grip rivets are often used to substitute conventional rivets where the thickness of installation materials can vary. The rivet simply expands to the size (within its range) and holds the two materials together.

7. Structural Rivets

Structural rivets are used to create a stronger assembly than standard stainless-steel pop rivets. They generate an intense amount of force and require a different tool to apply than a regular rivet.

8. Tri-Fold Rivets

Tri-Fold rivets, also called exploding rivets, have three cuts in the hat that cause the hat to fold outward when installed into three distinct wings. A tri-groove rivet has better strength and holding power than standard pop rivets.

Types of Washers

1. Backup Rivet Washers

Rivet backup washers are used to create a larger install diameter giving the rivet a better hold and more support. Backup washers can help to prevent the pull-through of a rivet.

2. Belleville Conical Washers

Belleville conical washers are a type of washer that adds extra tension to a fastener assembly. They are commonly used in stacks to increase the load, deflection or both to an assembly depending on the stack. These washers can be considered lock washers because they add tension and absorb vibration to an assembly.

3. Dock Washers

Dock washers are heavy-duty washers, often used to build docks. Also used in heavy-duty construction where a thick washer is needed, dock washers are similar to fender washers with a small inside diameter hole.

4. Fender Washers

Fender washers are round washers with a small inside diameter hole. Fender washers are used to prevent pull-through and provide a greater bearing surface under the fastener.

5. Fender Washers – Extra Thick

Fender washers are round washers with a small inside diameter hole. Extra thick fender washers are thicker than standard fender washers and are used to prevent pull-through and provide a greater bearing surface under the fastener.

6. Finishing Cup Washers

Finishing cup washers form a cup for the head of the screw or fastener to fit in, creating a finish flush with the top of the head. Used for finishing, cup washers are shaped like a cup.

7. Flat Washers

Flat washers are round outer diameter thin plates with a center hole punched to the size of the bolt or screw. Flat washers are used to distribute loads of threaded bolts, screws, and nuts evenly as the fastener is tightened.

8. Flat Washers – Extra Thick

Extra thick flat washers are thicker than standard flat washers. These washers are round outer diameter thin plates with a center hole punched to the size of the bolt or screw. Flat washers are used to distribute loads of threaded bolts, screws, and nuts evenly as the fastener is tightened.

9. Flat Washers – Military Standard

Military standard (MS) flat washers go through extensive inspection for chemical, physical and dimensional qualities. MS washers must meet specific inner diameter and outer diameter specifications.

10. Flat Washers – 900 Series

Flat washers in the 900 series are round and thinner than a standard flat washer with a smaller inside and outside diameter.

11. Lock Washers – Split Ring

Split ring lock washers are used to prevent nuts, bolts, and screws from vibrating loose. These washers are rings that are split at one point and bent into a helical shape.

12. Lock Washers – High Collar

High collar lock washers are designed to fit under the head of a socket cap screw. Split ring lock washers are used to prevent nuts, bolts, and screws from vibrating loose. These washers are rings that are split at one point and bent into a helical shape.

13. Lock Washers – External Tooth

External tooth lock washers are used for locking and tension. Round washers with teeth on the outside, used for maximum holding power. Must be used with fasteners with adequate head diameter.

14. Lock Washers – Internal Tooth

Internal tooth lock washers are used for locking and tension. A round washer with internal teeth, designed to prevent a nut or screw head from loosening with the strut action created by the teeth.

15. NAS Washers

NAS washers are round washers with smaller inner and outer diameters. Often used in military applications because of the strict measurement specifications.

16. Neoprene EPDM Washers

Round washers that are slightly beveled with a neoprene lining. Often used with a sharp point and self-drilling TEK screws to make a watertight seal around the screw or metal roofing or siding.

17. Structural Washers

Structural washers are thick and strong, built for heavy-duty applications such as construction. These washers can be found in steel beams and girder fastener assemblies.

18. Square Washers

Square washers are square in shape and maybe flat on both sides or flat on one side and beveled on one side. Often used with square head bolts, square washers prevent pull through and provide a larger surface area and greater hold than standard round flat washers.

Types of Concrete Anchors

1. Acoustical Wedge Anchors

Masonry acoustical wedge anchors are used to anchor and secured suspended wire to solid or hollow masonry materials. The fastener is inserted into the pre-drilled hole and then struck with a hammer which extends the wedge to hold the anchor in place.

2. Drop in Anchors

Drop-in anchors are internally threaded anchors that are commonly installed overhead and flush with the surface of the concrete. These anchors are commonly used to create handrails, lighting fixtures, and many other fixtures. They require a setting tool for installation.

3. Double Expansion Shield Anchors

Double expansion shield anchors are made for installing in softer materials or those of questionable quality. Their entire length expands in the hole to create a very secure hold. This expansion maximizes friction and holds on to the installation material.

4. Hammer Drive Pin Anchors

These anchors are used for lighter loads than other types of concrete anchors. Drive pins attach fixtures to masonry materials. A hammer is driven into the exposed head of the drive pin. This expands the base inside of the masonry material creating a hold.

5. Kaptoggle Hollow Wall Anchors

Kaptoggle hollow wall anchors are installed through a hole in the walls or block. Then a machine screw is screwed into the provided threading resulting in a secure hold. Kaptoggle wall anchors are proven to have better holding power than conventional types of hollow wall fasteners.

6. Lag Shield Expansion Anchors

These anchors are shielded expansion anchors used to hold lag screws. They expand outwards as lag screws are driven into them. This expansion presses against the installation surface creating a tight, secure hold. They also have very precise internal threading to allow the installation lag bolt to turn easily.

7. Machine Screw Anchors

Machine screw anchors are installed into masonry materials in a pre-drilled hole. Once placed inside the hole, a machine screw is threaded into the anchor and tightened. As the machine screw is tightened, a coned portion is pulled into the sleeve causing it to deform.

This deformation of the sleeve results in a tight wedge inside the hole that cannot be easily removed.

8. Masonry Screws

Concrete masonry anchors, also known as Tapcons, cut threads into concrete, brick or block when installed. Extended corrosion protection is gained from the blue climaseal coating. No hole spotting or inserts are required.

9. Plastic Toggle Anchors

Plastic toggle anchors are used in hollow walls or cinder blocks to create a fastening point for sheet metal screws. These anchors have legs that fold to enter a pre-drilled hole that expand when a screw is driven into them. Once the legs are fully expanded, the toggle anchor is securely in place.

10. Sammy’s Screws

Sammy Screws are used with threaded rods and save time by drilling into masonry materials. They have a female threaded portion to accept the threaded rod into it. Sammy’s are installed either vertically or horizontally and are commonly used due to their lower installation costs, flexibility, and ease of use.

11. Sleeve Anchors

Concrete masonry sleeve anchors consist of a threaded stud with an outwardly flared cone-shaped end, with a nut and a washer on the end. Tightening of the nut pulls the stud end into the expander sleeve, wedging it outwards and locking the anchor into the base material. Made for hollow concrete applications (ex. cinderblocks).

12. Toggle Wing Hollow Wall Anchors

Toggle Wings are used in situations when installing through a material. The wing can be bent in half and pushed through the material. Once it is all the way through the material it expands and can be screwed into to hold things in place against the rear side of the material.

13. Wedge Anchors

Concrete masonry wedge anchors are used to anchor and secure material and equipment to solid concrete masonry surfaces (ex. concrete slabs). Comprised of an anchor, a nut, and a washer. Used to fasten concrete to equipment, materials, generators, motors, pumps, pipe, strut, plastics, and wood.