20 Types of Fasteners Every Industrial Customer Should Know

In the world of industrial projects—whether you're building a petrochemical facility, assembling marine ships, or constructing power plants—there's an unsung hero holding everything together: fasteners. These small but mighty components are the backbone of structural integrity, the guardians of safety, and the quiet assurance that your systems will stand up to pressure, temperature, and time. As someone who's worked in or around industrial spaces, you know the difference between a project that thrives and one that falters often comes down to the fasteners you choose. They're not just "parts"; they're the trusty partners that turn blueprints into reality. Let's dive into 20 types of fasteners that every industrial customer should have in their toolkit, exploring why they matter and where they shine.

Fastener Type	Common Applications	Key Strength
Stud Bolt & Nut	Petrochemical facilities, pressure tubes, pipe flanges	Uniform clamping force under extreme pressure/temperature
Gasket	Between pipe flanges, heat exchanger tubes, boiler tubing	Creates leak-proof seals in high-stress environments
Steel Flanges	Pipeline works, structure works, power plants	Connects pipes while allowing easy access for maintenance
BW Fittings	High-pressure systems (e.g., oil/gas pipelines)	Strong, permanent joints with minimal flow restriction
SW Fittings	Small-diameter, high-pressure lines (e.g., hydraulic systems)	Easy installation in tight spaces with reliable sealing

1. Stud Bolt & Nut

If there's a "workhorse" in the fastener world, it's the stud bolt & nut. Picture this: you're securing a pipe flange in a petrochemical facility where temperatures swing from freezing to 500°F, and pressure builds to 10,000 psi. You need something that won't loosen, won't bend, and won't fail. Enter stud bolts—long rods threaded on both ends—and their matching nuts. Unlike regular bolts, they distribute clamping force evenly, making them ideal for critical joints in pressure tubes or custom big diameter steel pipe systems. In nuclear or aerospace applications, where failure isn't an option, high-grade stud bolts (often made from carbon alloy steel) are the silent sentinels ensuring everything stays put.

2. Gasket

Gaskets are the unsung heroes of leak prevention. Think about the last time you tightened a pipe flange—without a gasket, even the best stud bolts and nuts can't stop fluids or gases from seeping through microscopic gaps. Gaskets fill those gaps, conforming to irregularities in metal surfaces to create a seal that stands up to heat, pressure, and corrosive media. They come in all shapes and materials: rubber for low-pressure systems, graphite for high temperatures (like in boiler tubing), and metal for extreme conditions (think power plant heat exchanger tubes). In marine & ship-building, where saltwater corrosion is a constant threat, copper nickel gaskets are a go-to, proving that even the smallest fasteners can be the biggest protectors.

3. Steel Flanges

When you need to connect two pipes—whether in a simple pipeline work or a complex petrochemical facility—steel flanges are the way to go. These flat, circular discs with bolt holes act like "adapters," letting you join pipes, valves, or equipment quickly and securely. What makes them indispensable? They're reusable (unlike welded joints) and allow for easy inspection or repairs—critical in industries where downtime costs money. For high-pressure applications, like carbon alloy steel pressure tubes, weld neck flanges provide extra strength by extending a neck into the pipe. In contrast, slip-on flanges are perfect for low-pressure structure works, offering a cost-effective, easy-to-install solution. No industrial project is complete without a variety of these in stock.

4. BW Fittings (Butt-Welded Fittings)

For pipelines that can't afford weak points—think oil refineries or natural gas transmission—BW fittings are the gold standard. These fittings (elbows, tees, reducers) are welded directly to the pipe ends, creating a permanent, smooth joint that minimizes flow resistance and maximizes strength. Unlike threaded fittings, which can leak under high pressure, BW fittings form a monolithic bond with the pipe, making them ideal for custom big diameter steel pipe systems or high-temperature lines like those in power plants. If you've ever walked through a petrochemical facility and marveled at how pipes snake through tight spaces without a single leak, chances are BW fittings are doing the heavy lifting.

5. SW Fittings (Socket-Welded Fittings)

In tight spaces where butt-welding isn't feasible—like instrument lines or small-diameter hydraulic systems—SW fittings shine. These fittings have a socket (a recessed end) where the pipe is inserted, then welded around the perimeter. The result? A strong, compact joint that's easier to align than BW fittings, making them popular in marine & ship-building or aerospace applications where every inch counts. They're not just about convenience, though: SW fittings provide excellent resistance to vibration, which is why you'll often find them in machinery or equipment with moving parts. For industrial customers who value precision and space-saving design, SW fittings are a must-have.

6. Threaded Fittings

Sometimes, you need a joint you can take apart—and that's where threaded fittings come in. These fittings have internal or external threads that screw into pipes, making installation and disassembly a breeze (no welding required). They're perfect for low-pressure systems, like water lines in structure works or small-diameter tubes in industrial valves. While they're not ideal for extreme pressure or temperature, their versatility makes them a staple in warehouses and job sites. Think about the last time you needed to reconfigure a pipe layout quickly—threaded fittings let you do that without calling in a welder, saving time and hassle.

7. Socket Head Cap Screw

When you need a fastener that sits flush with the surface (no protruding head to catch on equipment) and delivers high torque, socket head cap screws are your answer. These screws have a cylindrical head with a hexagonal socket (Allen key) drive, allowing them to be tightened in tight spaces. They're common in machinery, where a clean, low-profile look matters, and in aerospace, where weight and aerodynamics are critical. Ever wondered how aircraft components stay securely fastened without adding extra bulk? Chances are, socket head cap screws are part of the solution, proving that sometimes, the most effective fasteners are the ones you barely notice.

8. Hex Head Bolt

The hex head bolt is the "everyman" of fasteners—reliable, versatile, and instantly recognizable by its six-sided head. You'll find them everywhere: holding together steel structures in construction, securing machinery in factories, and even in custom steel tubular piles for marine foundations. What makes them so popular? Their simplicity. A wrench or socket fits easily over the hex head, allowing for quick tightening, and they come in a range of materials, from carbon steel for everyday use to stainless steel for corrosive environments (like coastal marine projects). When you need a fastener that's easy to source, easy to use, and tough as nails, hex head bolts deliver.

9. Carriage Bolt

If you've ever built a wooden deck or installed a guardrail, you've probably used a carriage bolt. These bolts have a smooth, domed head and a square neck under the head that prevents them from spinning when tightened—perfect for applications where one side of the joint isn't accessible (like securing a metal bracket to wood). In industrial settings, they're often used in structure works, where wood or soft materials need a secure, rattle-free connection. Their low-profile head also makes them a favorite in places where safety is key—no sharp edges to catch on tools or clothing.

10. Eye Bolt

When you need to lift heavy equipment or suspend loads, eye bolts are non-negotiable. These bolts have a loop (or "eye") at one end, allowing you to attach ropes, chains, or hooks, and threads at the other end to secure them to a structure. They're critical in construction, marine & ship-building, and manufacturing, where moving large components (like custom alloy steel tubes or industrial valves) safely is a top priority. The key? Choosing the right eye bolt for the load—never use a bent or damaged one, as the consequences of failure can be catastrophic. When used correctly, they're the "lifting partners" that keep your team safe.

11. Machine Screw

Machine screws are the workhorses of small-scale fastening, used to secure parts together in machinery, electronics, and appliances. They're similar to bolts but smaller, with finer threads, and often come with slotted, Phillips, or hex heads. What makes them indispensable? Their precision. They're designed to screw into tapped holes or nuts, making them ideal for securing thin materials or delicate components (like the panels on industrial control boxes). If you've ever taken apart a piece of equipment to repair it, you've likely encountered machine screws—they're the fasteners that hold the little things together, so the big things can work.

12. Set Screw

Set screws are the "hidden holders" that keep moving parts in place. Unlike regular screws, they don't have a head—instead, they have a drive (slotted, hex, or Allen) on one end and a pointed, flat, or cupped tip on the other. When tightened into a threaded hole, the tip presses against another part, creating friction to prevent slipping. They're everywhere: in pulleys (to lock them onto shafts), in handles (to keep them from spinning), and even in pipe fittings (to secure valves in place). In marine & ship-building, set screws are used to lock propeller shafts, ensuring they rotate smoothly without shifting. Small in size, but big on responsibility—set screws prove that fasteners don't need to be flashy to be essential.

13. Spring Washer

Vibration is the enemy of fasteners—it can loosen even the tightest bolts over time. That's where spring washers come in. These washer have a split, helical design that acts like a spring: when you tighten a nut or bolt, the washer compresses, then pushes back against the nut, maintaining tension and preventing loosening. They're a must in machinery, engines, and any system with moving parts (like the pumps in power plants or the engines in marine vessels). Think about a car engine—without spring washers, the constant vibration would rattle bolts loose in minutes. In industrial settings, they're the silent guards that keep your fasteners tight, day in and day out.

14. Flat Washer

Flat washers are the unsung protectors of surfaces. Placed between a nut/bolt head and the material being fastened, they distribute the load of the fastener over a larger area, preventing the head from sinking into soft materials (like wood or plastic) or damaging delicate surfaces (like painted metal). They also help align bolts in oversized or misaligned holes, making installation easier. While they might seem simple, flat washers are essential in structure works, where uneven surfaces are common, and in custom projects where material integrity is key. Next time you install a bolt, add a flat washer—your surfaces will thank you.

15. Cotter Pin

When you need a fastener that's quick to install and remove (but won't fall out on its own), cotter pins are the answer. These U-shaped metal pins have two tines that bend after insertion, locking them in place. They're commonly used with clevis pins or castellated nuts (nuts with slots) to secure hinges, linkages, or axles. In marine & ship-building, cotter pins secure rudder assemblies and steering mechanisms—critical systems where failure could lead to disaster. What makes them great? They're reusable (just straighten the tines to remove) and inexpensive, making them a favorite for temporary or maintenance-heavy applications.

16. R-Clip

R-clips (or retaining clips) are the faster, easier alternative to cotter pins. Shaped like the letter "R," they slip into a hole in a shaft or pin, with the curved part springing back to lock them in place. They're ideal for applications where you need to remove the clip frequently—like in agricultural machinery or conveyor systems—since they can be popped out with a screwdriver or pliers in seconds. In industrial valves, R-clips often secure handles or levers, allowing for quick adjustments without tools. They're small, simple, and surprisingly strong—proving that sometimes, the best fasteners are the ones that save you time.

17. Clevis Pin

Clevis pins are the backbone of hinged joints. These cylindrical pins have a head on one end and a hole (for a cotter pin or R-clip) on the other, making them perfect for connecting two parts that need to pivot (like a tow hitch or a linkage in a machine). They're strong, durable, and designed to handle shear loads (forces that try to cut the pin in half), which is why they're common in construction equipment and marine hardware. In custom steel tubular piles, clevis pins might connect bracing components, allowing for slight movement while maintaining structural integrity. When you need a joint that's both flexible and tough, clevis pins deliver.

18. Toggle Bolt

Hanging heavy objects from drywall or hollow walls? Toggle bolts are your secret weapon. These bolts have a spring-loaded "toggle" that folds flat for insertion into a hole, then springs open behind the wall to create a large anchor. When tightened, the toggle pulls against the back of the wall, distributing the load and preventing the bolt from pulling out. They're a lifesaver in industrial settings where you need to mount equipment (like control panels or tool racks) to non-structural walls. While they're not for extreme loads, they're indispensable for quick, secure installations in spaces where you can't access the back of the wall.

19. Expansion Bolt

For fastening to concrete, brick, or masonry— common in structure works or outdoor industrial projects—expansion bolts are the way to go. These bolts have a split sleeve or cone that expands when the bolt is tightened, gripping the surrounding material tightly. They're used to secure everything from steel beams to machinery bases, and they're designed to handle heavy loads (some can hold hundreds of pounds). In power plants, expansion bolts might secure heat exchanger tubes to concrete foundations, ensuring they stay put even during thermal expansion. When you need a fastener that's anchored in stone, not just surface-deep, expansion bolts are the gold standard.

20. Copper Nickel Flanges

Last but certainly not least, copper nickel flanges deserve a spot on this list—especially for industrial customers in marine, coastal, or corrosive environments. Made from an alloy of copper and nickel (often with small amounts of iron or manganese), these flanges resist saltwater corrosion, biofouling (the buildup of marine organisms), and erosion, making them ideal for ship-building, offshore oil rigs, and desalination plants. They're also great for heat exchanger tubes in coastal power plants, where seawater is used as a coolant. What sets them apart? They combine the strength of steel with the corrosion resistance of copper, making them a long-term investment that saves on replacement costs. When you're working in harsh conditions, copper nickel flanges aren't just a choice—they're a necessity.

Fasteners are the silent architects of industrial success. From the stud bolts holding together a petrochemical reactor to the gaskets sealing a heat exchanger tube, each type plays a unique role in ensuring your projects are safe, reliable, and built to last. As you source wholesale or custom components for your next job—whether it's pipeline works, marine construction, or power plant upgrades—remember that the right fasteners aren't an afterthought; they're the foundation of quality. By understanding these 20 types, you're not just buying parts—you're investing in peace of mind. After all, in industrial work, the best projects are the ones where the fasteners do their job so well, you never have to think about them again.