Different Types of Fasteners Used in Manufacturing: Screws, Bolts and More

Fasteners are small components, but they play an essential role in product manufacturing and final assembly.

They are used to join parts in machinery, vehicles, electronic products, sheet metal enclosures, furniture and many other products.

Some fasteners create removable joints that allow components to be maintained or replaced. Others form permanent connections that usually require the fastener to be damaged during removal.

Common types of fasteners include screws, bolts, nuts, rivets, threaded inserts, threaded rods and washers.

Each type works differently and is suited to different materials, loads and installation conditions.

This guide explains the main types of fasteners used in manufacturing, how they work and where they are commonly used. It also provides basic guidance for selecting fasteners and designing parts with threaded holes, rivet holes and other fastening features.

What Is a Fastener?

A fastener is a mechanical component used to join two or more parts.

Most fasteners create a connection through threads, clamp force, interference or controlled deformation.

Unlike welding, brazing or adhesive bonding, many fastening methods allow the joined components to be separated without damaging the main parts.

However, not every fastener creates a removable joint.

Screws, bolts and nuts generally support disassembly and reassembly. Rivets usually form permanent joints and must be drilled out or otherwise removed before the components can be separated.

Fasteners may also perform functions beyond holding parts together.

Depending on the design, a fastener may:

• maintain component alignment
• locate one part relative to another
• distribute clamp load
• support adjustment
• prevent axial or rotational movement
• allow future maintenance

Threaded and Non-Threaded Fasteners

Fasteners are commonly divided into threaded and non-threaded types.

Threaded fasteners use matching external and internal threads to create a connection.

Common threaded fasteners include:

• screws
• bolts
• nuts
• studs
• threaded rods
• threaded inserts

Some screws engage directly with the joined material. Others require a tapped hole, nut or threaded insert.

Bolts commonly pass through clearance holes and engage with nuts or other internally threaded components.

Non-threaded fasteners do not rely on matching screw threads.

Common examples include:

• rivets
• dowel pins
• spring pins
• retaining rings
• clips

These fasteners may use deformation, interference, spring force or a shaped groove to hold components in position.

Washers are not always classified as fasteners because they do not normally create a joint by themselves.

However, washers are commonly used with screws, bolts and nuts to distribute load, protect component surfaces or support sealing and locking functions.

The correct fastener depends on the joined material, material thickness, applied load, installation access, operating environment and whether the joint must be removable.

What Are Fasteners Made From?

Fasteners are made from metals, plastics and other engineering materials.

Carbon steel is widely used because it offers a practical balance of strength, availability and cost. Alloy steel is selected when higher strength or hardness is required.

Stainless steel provides better corrosion resistance and is commonly used in outdoor, food-processing and humid environments.

Aluminum fasteners are lightweight but generally support lower loads than steel. Brass offers corrosion resistance, electrical conductivity and an attractive appearance.

Titanium combines low weight, high specific strength and excellent corrosion resistance, although it is more expensive.

Plastic fasteners provide electrical insulation, low weight and chemical resistance, but they are usually limited to lower-load applications.

Fasteners may also receive zinc plating, nickel plating, black oxide or passivation to improve corrosion resistance or appearance.

The correct material depends on strength, weight, environment, temperature, cost and compatibility with the joined components.

What Materials Can Fasteners Be Used With?

Fasteners can be used with metals, plastics, wood, concrete and composite materials.

Machined metal parts commonly use machine screws, bolts, studs and threaded inserts.

Sheet metal assemblies may use sheet metal screws, rivets, rivet nuts or self-clinching fasteners because thin sheet may not provide enough depth for a strong tapped thread.

Plastic parts often use thread-forming screws or threaded inserts, especially when repeated assembly is required.

Wood products typically use wood screws or lag screws, while concrete structures require anchor bolts or dedicated masonry fasteners.

Composite materials may need inserts, backing plates or larger washers to distribute load.

The correct option depends on material thickness, strength, installation access and whether the joint must be removable.

Fastener Standards

Fastener standards help ensure that screws, bolts, nuts and related hardware meet consistent dimensional and performance requirements.

Common standards are published by organizations such as ISO, ASME, DIN and ASTM.

A standard may define:

• thread diameter and pitch
• head style
• length
• tolerance
• material grade
• mechanical properties
• coating or finish
• inspection requirements

Using a recognized standard helps designers, suppliers and inspectors work from the same specification.

A drawing should not identify a critical fastener only as an “M6 screw.”

The pitch, length, head type, material, strength grade and finish should also be defined to reduce substitution and assembly problems.

Screws

Screws are threaded fasteners that join components by engaging with a tapped hole, nut, threaded insert or the joined material itself.

Some screws require an existing internal thread. Others can form or cut a mating thread during installation.

Unlike many bolts, screws may be installed directly into one of the joined parts without using a separate nut.

For custom components, tapped holes, countersinks and counterbores can be produced through Baosheng’s CNC machining services.

Types of Screws

Machine screws: These screws have uniform machine threads and usually engage with a tapped hole, nut or threaded insert. They are commonly used in machinery, electronics and metal assemblies.

Sheet metal screws: These screws use sharp threads designed to engage with thin metal. Joint strength depends on sheet thickness, pilot-hole size and screw diameter.

Self-tapping screws: Self-tapping screws form or cut their own mating threads in a prepared hole. They are commonly used with sheet metal and plastic.

Self-drilling screws: These screws have a drill-shaped point that creates the hole before forming the thread. They are often used in sheet metal construction and enclosures.

Wood screws: Wood screws use coarse threads that grip wood fibers. Pilot holes may be needed near edges or in hardwood to reduce splitting.

Set screws: Set screws are usually headless and secure gears, collars or pulleys to shafts. Different tip styles affect holding force and surface marking.

Types of Screw Drive

The screw drive is the feature engaged by the installation tool.

Common drive types include:

• Slotted: Simple, but more likely to slip during installation.
• Phillips: Widely used in consumer products and general assembly.
• Hex socket: Provides good torque transfer in limited space.
• Torx: Reduces cam-out and supports reliable powered installation.
• External hex: Suitable for higher torque where wrench access is available.

Drive selection affects tool access, torque transfer, assembly speed and maintenance.

The correct screw also depends on material thickness, thread engagement, required clamp force and how often the joint will be disassembled.

Bolts

Bolts are externally threaded fasteners commonly used with nuts or internally threaded components.

In a typical bolted joint, the bolt passes through clearance holes in the joined parts and engages with a nut on the opposite side.

Tightening the bolt or nut creates clamp force that holds the components together.

Unlike self-tapping screws, bolts do not usually form their own mating threads during installation.

However, the distinction between a screw and a bolt is not always absolute. Some standards classify fasteners according to their intended use, head style or installation method.

Types of Bolts

Hex bolts: Hex bolts have a six-sided head and are tightened with a wrench or socket. They are widely used in machinery, vehicles and structural assemblies.

Carriage bolts: These bolts have a rounded head and a square section beneath it. The square neck helps prevent rotation during tightening.

U-bolts: U-bolts have a curved body with threaded ends. They are commonly used to secure pipes, tubes and cylindrical components.

Eye bolts: Eye bolts include a loop for attaching cables, ropes or lifting equipment. Not every eye bolt is suitable for lifting, so the rated use should be confirmed.

Flange bolts: Flange bolts include an enlarged flange beneath the head. The flange distributes load and may replace a separate washer in some assemblies.

Bolt selection depends on more than diameter and length.

The designer should also consider:

• tensile and shear loads
• material and strength grade
• thread engagement
• installation access
• vibration
• corrosion environment

A higher-strength bolt is not automatically suitable for every joint. The nut, tapped hole and joined materials must also support the required load.

Nuts

Nuts are internally threaded fasteners commonly used with bolts, studs and threaded rods.

When a nut is tightened, its internal thread engages with the external thread of the mating fastener and creates clamp force between the joined components.

Most nuts can be removed, making them suitable for assemblies that require maintenance or adjustment.

The nut material, thread size and strength grade should be compatible with the mating bolt or stud.

Types of Nuts

Hex nuts: Hex nuts have six external flats and are tightened with a wrench or socket. They are widely used in machinery, vehicles and general industrial assemblies.

Flange nuts: These nuts include an enlarged flange that distributes load over a wider area. The flange may replace a separate washer in some applications.

Lock nuts: Lock nuts include a feature that increases resistance to unintended rotation. Common designs use a nylon insert or controlled deformation of the metal thread.

Wing nuts: Wing nuts have two projections that allow manual tightening and removal. They are suitable for light-duty assemblies that require frequent tool-free adjustment.

Weld nuts: Weld nuts are permanently attached to sheet metal and provide a fixed internal thread. They are useful when later assembly must be completed from one side.

Locking nuts can improve resistance to vibration, but they do not replace correct preload or joint design.

Nut selection should consider thread compatibility, clamp load, operating temperature, vibration, corrosion and available tool access.

Rivets

Rivets are non-threaded fasteners that usually create permanent joints.

A typical rivet has a factory-formed head and a shank. During installation, the opposite end of the shank is deformed to clamp the joined materials together.

Unlike screws and bolts, rivets are not normally removed without damaging the fastener.

They are commonly used in sheet metal enclosures, vehicles, appliances and lightweight structures.

Types of Rivets

Blind rivets: Blind rivets can be installed from one side of the assembly. They are widely used in enclosures, panels and hollow sections where rear access is limited.

Solid rivets: Solid rivets have a solid shank and require access to both sides during installation. They are used in aircraft structures, heavy equipment and other high-strength applications.

Semi-tubular rivets: These rivets have a partially hollow end that requires less force to deform. They are common in hinges, furniture and light mechanical assemblies.

Structural rivets: Structural rivets provide higher shear and tensile strength than standard blind rivets. They are used in transportation equipment and demanding sheet assemblies.

Rivet selection should consider:

• hole diameter
• grip range
• sheet thickness
• edge distance
• material compatibility
• required shear and tensile strength

For custom parts, Baosheng’s sheet metal fabrication services can support rivet holes, countersinks and related mounting features.

The rivet should be selected as part of the complete joint rather than by diameter alone.

Miscellaneous Threaded Fasteners

Some threaded fasteners do not fit neatly into the categories of screws, bolts and nuts.

Threaded inserts, threaded rods and studs are commonly used when a component needs a reusable internal thread, extended clamping length or headless fastening feature.

Threaded Inserts

Threaded inserts are installed into plastic, soft metal or thin sheet to provide a stronger internal thread.

They are useful when the parent material cannot support repeated screw installation.

Common types include:

• heat-set inserts
• helical inserts
• rivet nuts
• self-clinching inserts

Threaded inserts may also be used to repair damaged threads.

The correct insert depends on the parent material, installation method, wall thickness and required pull-out resistance.

Threaded Rods and Studs

Threaded rods and studs are headless fasteners used with nuts or tapped holes.

Threaded rods usually have threads along most or all of their length.

Studs may have threads on one or both ends and are commonly used in machinery, flanges, equipment mounting and long clamping assemblies.

Thread engagement, alignment, exposed thread length and corrosion protection should be considered during design.

Washers

Washers are thin components placed beneath a screw head, bolt head or nut.

They do not usually create a joint by themselves, but they can distribute load, protect surfaces, provide spacing or support sealing and locking functions.

Common washer types include:

• Flat washers: Spread clamp load over a larger area.
• Fender washers: Use a larger outside diameter for thin or soft materials.
• Spring washers: Provide limited elastic resistance in some assemblies.
• Sealing washers: Include a sealing material to help prevent fluid or moisture leakage.

Washer selection depends on fastener size, contact material, load and operating environment.

A washer can support a correctly designed joint, but it cannot correct insufficient thread engagement or improper preload.

How to Choose the Right Fastener

The correct fastener depends on how the joint will be assembled, loaded and maintained.

A screw may be suitable for a removable general assembly, while a rivet may be more practical for a permanent sheet metal joint.

Fastener selection should also consider:

• joined material
• material thickness
• tensile or shear load
• access from one or both sides
• maintenance requirements
• vibration
• corrosion environment
• production volume

For example, a bolt-and-nut joint usually requires access to both sides of the assembly.

A blind rivet or rivet nut may be more suitable when only one side is accessible.

Plastic parts that require repeated assembly often benefit from threaded inserts, while thin sheet may require rivet nuts, weld nuts or self-clinching hardware.

The fastener should be selected as part of the complete joint, not as an isolated component.

Designing Fastener-Ready Parts

Fastener selection should be considered together with the design of the joined components.

Hole size, thread depth, material thickness and tool access can all affect assembly quality.

Holes and Threads

Machine screws usually require a tapped hole, nut or threaded insert.

Bolts commonly pass through clearance holes before engaging with a nut or threaded component.

Countersunk screws require a matching countersink angle and depth, while socket head screws may need a counterbore.

Blind tapped holes should include enough depth for thread engagement, tool clearance and chip space.

Thin Sheet and Plastic

Thin sheet may not provide enough thickness for a reliable tapped thread.

Rivet nuts, self-clinching fasteners or weld nuts may provide a stronger reusable connection.

Plastic parts may use thread-forming screws for limited assembly cycles.

Where repeated assembly or higher pull-out resistance is required, threaded inserts are often more suitable.

Installation Access

The design must provide enough space for the screw head, nut and installation tool.

Bolt-and-nut joints usually require access from both sides.

Blind rivets and rivet nuts can be installed from one side.

Clearance should also be checked around walls, bends, ribs and nearby components.

Fastener features should be reviewed together with the material, manufacturing process and final assembly method.

How Baosheng Can Help with Fastener-Ready Parts

Baosheng manufactures custom components with the holes, threads and mounting features required for fastener assembly.

Through our CNC machining services, we can produce:

• tapped holes
• thread-milled features
• clearance holes
• countersinks
• counterbores
• threaded insert locations

Our sheet metal fabrication services can support:

• laser-cut mounting holes
• rivet holes
• rivet nut locations
• self-clinching hardware
• weld nut features
• formed mounting details

Inspection may include thread gauges, hole diameter, hole position, countersink dimensions and installed hardware checks.

Send your 2D drawing or 3D model with the material, thread specification, hole dimensions, insert requirements and quantity.

Our team can review the machining, sheet metal and inspection requirements before quoting.

Conclusion

Fasteners may look simple, but different types serve different materials, loads and assembly requirements.

Screws, bolts, nuts, rivets, threaded inserts and washers should be selected according to joint strength, installation access, maintenance needs and operating environment.

For custom parts with threaded holes, rivet holes, countersinks or insert features, send Baosheng your 2D drawing or 3D model.

Our team can review the material, fastening features, manufacturing process and inspection requirements before providing a quote.