What Are the Different Types of Fasteners?
Fasteners hold equipment together, secure structural components, and keep machinery running under pressure, vibration, and heavy loads. But there are many different types of fasteners, and if you pick the wrong one, you risk equipment failure and safety hazards.
In turn, pick the right one, and your connections stay solid through years of hard use. This handy guide covers the main types of fasteners that you need to know, including threaded fasteners, non-threaded fasteners, and specialty options for industrial applications.
What Is a Fastener?
A fastener is a mechanical component that joins two or more parts together.
Fasteners create permanent or removable connections depending on the job, and they range from simple bolts and screws to specialized hardware for high-stress applications.
In construction, mining, automotive, and heavy equipment work, fasteners handle loads, resist corrosion, and survive extreme conditions. They're usually rated by strength grade, material, and coating to match specific environmental and mechanical demands.
1. Threaded Fasteners
Bolts
Bolts are externally threaded fasteners that pass through holes in parts and secure them with a nut on the opposite side. They create strong mechanical connections that you can disassemble when needed.
Common types include:
Hex head bolts have a six-sided head that accepts a wrench or socket, and they're standard across construction, machinery, and structural work.
Carriage bolts have a round head with a square section below it that locks into the material, preventing rotation during installation, and they work well for wood-to-metal connections.
Eye bolts have a looped head for attaching cables, chains, and rigging hardware, and they handle lifting and pulling loads in equipment and rigging applications.
Bolts get used in heavy equipment assembly, structural steel connections, machinery maintenance, and virtually anywhere you need a strong yet removable connection.
Learn more about the different types of bolts and why you need them.
Screws
Screws make a connection in a way that's different from bolts. They either cut their own threads into material or thread into pre-tapped holes, and they don't require a nut on the opposite side.
Main types of screw fasteners include:
Machine screws thread into tapped holes or work with nuts, and they come in various head styles for different applications.
Socket screws use an internal hex socket in the head, allowing higher torque application in tight spaces, and they're common in machinery and equipment assembly because of their strength.
Hex cap screws look similar to hex bolts but have tighter tolerances and full threading under the head to handle precision assembly and high-stress connections.
Self-tapping screws cut their own threads as they're driven into material, and they work in sheet metal, plastic, and thin materials where pre-drilling isn't practical.
Self-drilling screws combine a drill point with threading, eliminating the need for pilot holes, so they speed up installation in metal panels and structural work.
Learn more about the screw fasteners that go through metal, if that's what you need.
Nuts
Nuts thread onto bolts and screws to clamp parts together. They distribute clamping force and provide tension to keep connections tight.
You may need:
Hex nuts for standard bolted connections across all industries where wrench or socket access is available.
Lock nuts for machinery, equipment, and vibration-prone applications, especially where loosening would cause failures or safety hazards.
Wing nuts for applications that need frequent adjustment or removal without tools, like temporary fixtures or access panels.
Overall, nuts provide the clamping force that makes bolted connections work, but it's important to choose the right type to prevent loosening under load.
Studs and Threaded Rods
Studs are threaded fasteners with no head, threaded on both ends or along the entire length. One end threads into a tapped hole and the other accepts a nut.
Studs work better than bolts when you need to remove parts repeatedly without wearing out the threads in expensive housings.
They also solve access problems when there's no room for a bolt head. Flange connections, exhaust manifolds, and cylinder heads commonly use studs because maintenance crews need to pull parts off without damaging the base threads.
Threaded rods are fully threaded along their entire length and function as adjustable fasteners.
They hang pipe and electrical conduit, brace structures, and provide support where you need to fine-tune positioning or span variable distances.
2. Non-Threaded Fasteners
Rivets
Rivets create permanent connections by deforming the fastener after installation. You insert a rivet through aligned holes in two parts and apply force to the tail end. The tail expands and forms a second head that clamps the parts together.
Here are some of the most popular types of rivets:
Solid rivets for structural steel, aircraft assembly, and heavy-duty applications.
Blind rivets for installations where you can only access one side of the work, like enclosed panels or tube assemblies.
Drive rivets for light-duty connections in sheet metal, signage, and applications where installation needs to be fast.
Rivets handle metal fabrication, structural connections, and applications where you need permanent fasteners, especially under vibration.
Pins
Pins align parts, create pivot points, and hold components in position. They don't use threads and typically rely on friction fit or secondary locking methods.
You may need:
Dowel pins for alignment in machinery, tooling, and equipment assembly where parts need to be located accurately.
Cotter pins for securing castle nuts, clevis pins, and linkages with a simple locking mechanism that's easy to remove.
Clevis pins for creating pivot points in rigging hardware, linkages, and equipment where parts need to rotate or articulate.
Pins often show up throughout machinery and equipment industries.
Retaining Rings
Retaining rings fit into grooves on shafts or inside bores to hold components in position. They create a shoulder that prevents axial movement.
Internal rings fit inside bores and hold components from moving outward. In turn, external rings fit onto shafts and prevent components from sliding off.
All of these are common in bearing assemblies, gear systems, and jobs where machinery components need to stay positioned on shafts without using threaded fasteners or collars.
3. Anchors
Anchors fasten objects to concrete, masonry, and other solid materials. They create mechanical connections in substrates where you can't thread or clamp.
Popular choices include:
Wedge anchors for attaching equipment bases, structural members, and heavy machinery to concrete.
Sleeve anchors for mounting brackets, handrails, and lighter equipment to concrete or block.
Drop-in anchors for flush-mount applications in concrete where the anchor body sits below the surface and accepts threaded rod or bolts.
Anchors often handle the foundation connections for equipment, structures, and mounted hardware across construction and industrial facilities.
4. Washers and Supporting Hardware
Washers
Washers sit between fastener heads or nuts and the surface being clamped. They spread the load over a larger area, protecting the material and preventing damage during tightening.
Common types include:
Flat washers for distributing clamping force, protecting surfaces, and filling gaps in standard bolted connections.
Lock washers for preventing loosening in vibration-prone applications like machinery, equipment, and vehicle assembly.
Learn more about automotive fasteners and how to choose the right ones.
Other Supporting Hardware
There are a few types of supporting hardware.
Hose clamps secure hoses to fittings and prevent leaks under pressure. They adjust to different sizes and provide constant tension as hoses expand or contract.
Clips and clamps hold components in position, route cables and lines, and secure parts, especially when traditional fasteners won't work.
Overall, supporting hardware completes fastening systems and handles the connections that bolts and screws can't address alone.
How to Choose the Right Fastener
It's important to think about the materials that you're joining when choosing from different types of fasteners. Naturally, steel-to-steel connections need different fasteners than steel-to-wood or steel-to-concrete.
Another thing to consider is the loads involved. Static loads, dynamic loads, and shock loads all affect which fastener grade and type will hold up.
Plus, environmental conditions matter, too. Outdoor applications, corrosive environments, and high temperatures require specific materials and coatings to prevent failure.
Not sure which type of fastener fits your job? Contact our team or check out our product guide below:
What Is the Most Commonly Used Fastener?
It really depends on your industry. That said, hex bolts with hex nuts are some of the most commonly used fasteners because they're versatile, strong, and easy to install with standard tools.
You'll often find them in construction, machinery, automotive work, and other applications that need a reliable and removable connection.
Get Different Types of Fasteners for the Toughest Jobs
D&T Enterprises carries fasteners for construction crews, mining operations, automotive shops, manufacturing plants, and heavy equipment facilities.
We'll source the bolts, screws, nuts, washers, and all the hardware you need in the right sizes and finishes for your application.
After we receive your request, we either pull your parts from our inventory or place orders with our suppliers to get everything to you through local delivery or shipping.
We've been doing this work since 1976, serving operations throughout Virginia and across the country. With D&T, you get high inventory capacity with personal attention.
Learn more about our products or get a quote so we can handle your order without delay!
