What is a Fastener?

Under the term fasteners there is a broad category of products which can be referred to, such as screws, bolts and nuts, rivets etc. All these products share a common purpose: to mechanically hold objects together. Obviously, glue can fulfill this function, but glue is not a type of fastener.

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

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.

Screws

One of the most commonly known type of fasteners are screws. The threaded shaft of the screw gives them a durable holding power. The head of a screw is equipped with a sort of notch e.g. slotted, pozidrive, phillips, torx etc. to be able to process the screw in the product. A screw doesn’t need another component to hold them in place, unlike a bold which requires a nut. In general you use a drill to make a pilot hole in the material and then use a (powered) screwdriver to drive the screw in place. Screws come in a wide variety of types, most common screws:

• Wood screws have coarse threads and a tapered head.
• Deck screws are similar to wood screws, but include self-tapping designs and corrosion resistance for outdoor applications.
• Drywall screws feature a self-tapping head that can countersink without causing damage to drywall.
• Sheet metal screws have sharper threads for connecting metal to other materials.
• Machine screws have a uniform thickness and don’t taper off at the bottom.
• MDF screws can self-tap without splitting the material.

Nails

Nails are probably one of the oldest type of fasteners and have been used since ancient times. Still they are an everyday household items. The difference between a nail and a screw is that 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 a better choice of some purposes. Many type of nails take their names from their application. They typically have specific characteristics designed for working with the materials or application at hand. Most common known type of nails:

• Common nails have a thicker shank for greater holding power for many different applications, but the thick head will be visible on most projects.
• Box nails offer easier driving with a steel construction and diamond-point tip.
• Brad nails can easily blend into wood trim.
• Finishing nails are for more detailed work and have a small, flat head designed to blend in with project finishes, such as those on crown molding.
• Drywall nails are designed for easy concealment and reduced slippage.
• Flooring nails are designed for use with various flooring materials.
• Framing nails can include a variety of styles, often designed for flush installation and easy concealment.
• Roofing nails have a wide head and are often corrosion-resistant.

Bolts & Nuts

Bolts and nuts are commonly used together. These two items work in tandem to hold components together. In generel, you insert the bolt through the two parts which needs to be joined, then fasten it in place with the nut on the end. Most common known type of bolts:

• Carriage bolts have domed or countersunk heads with a square component under the heat to keep the bolt from moving while tightening the nut.
• Flange bolts include a circular flange beneath the head for distributing loads evenly.
• Plow bolts are for heavy-duty applications, such as heavy equipment, with non-protruding heads.
• Hex-head bolts are six-sided with machine threads.
• Square-head bolts have square heads, offering an easier grip for wrenches.

And the most commonly used type of nuts:

• Coupling nuts are hex-shaped and join two male threads together.
• Flange nuts have a wide, serrated flange on one end that serves a similar function as a washer but without any added movement.
• Hex nuts are the most common variety, featuring a hex shape and internal threads.
• Lock nuts include designs to prevent loosening due to vibrations.
• Slotted nuts have sections cut out to create a locking mechanism with the help of a cotter ping.
• Square nuts feature a square shape for greater surface area.
• Wheel nuts are designed for securing wheels onto vehicles.

Washers

Nuts and bolts or screws can function on their own, but sometimes, you’ll want to add a washer in between. A washer is a flat disc with an opening in the center. This little piece can distribute the fastener’s load more evenly across the surface of the material. Other uses are as a spacer, spring (wave washer), wear pad, preload indicating device, locking device, and to reduce vibration (rubber washers). ost common known type of washers:

• Beveled washers add stability when attaching unparallel surfaces.
• Flat washers are round and thin.
• Lock washers use various mechanisms to prevent nuts, screws and bolts from vibrating loose.
• Structural washers are thicker and used in heavy-duty applications.

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. Some common types of anchors include:

• Internally threaded anchors
• Externally threaded anchors
• Masonry screw and pin anchors
• Screw anchors
• Hollow wall anchors
• Sleeve anchors
• Drive anchors

Threaded Studs

Threaded studs often referred to as a rods, is a rod of varying length that is threaded in a helical structure.

Similar in appearance to a screw, the threading extends around and along the rod to cause rotational movements when in use. Threaded rods combine linear and rotational movement to create strong resistance to pressure.

The direction of the rotation caused by a threaded rod depends on whether the rod has a right-hand thread, left-hand thread, or both.

Designed to withstand very high levels of pressure and tension, threaded rods are a common fixing for support systems and used for a variety of applications.

Rivets

As in general all fasteners are being used to create a non permanent joint, a rivet creates a permanent joint between two objects. They consist of a cylindrical shaft with a head on one end and a tail on the other. You use a unique tool to expand the tail, so the rivet stays in place. Rivets are remarkably durable, compared to other types of fasteners. Some common types of rivets are:

• Blind rivets
• Semi-tubular rivets
• Solid rivets
• Split rivets
• Drive rivets

Clamps

Pipe clamps or pipe fixings, are best defined as the support mechanism for suspended pipes, whether that be horizontal overhead or vertical, adjacent to a surface. They are vital in ensuring all pipes are fixed securely while also allowing for any pipe movement or expansion that may occur.

Pipe clamps come in many variations as the requirements for pipe fixing can range from simple anchoring in place, to more complex scenarios involving pipe movement or heavy loads. It is essential that the right pipe clamp is used to ensure the integrity of the installation. Pipe fixing failure can cause significant and costly damage to a building so it is important to get it right. The most common types of clamps are:

• Standard clamps are typically fixed using two screws – one on either side of the clamp. They can be lined or unlined, depending on the application and there tends to be a wide range of sizes to choose from.
• Plastic clamps are mainly used on plastic pipes or domestic copper pipes. They are perfect for light loads and smaller diameter pipes. They are also great for jobs where lots of clamps are required due to their quick installation time.
• Traditional clamps include split bands, U Bolts and Saddle Clamps, most commonly used to hold steel or copper pipes. They have no internal lining so are best suited to pipes where there are no additional variables to be considered such as temperature or noise insulation.
• Heavy duty clamps have a high safe working load, so are designed for use where a heavy load support is required. They can be used indoors and outdoors and are available both with and without lining. They have modern features to make them easier to fit than traditional clamps. 

Pins

There are several distinct types of fastener, which may be referred to as a pin. These include small headless nails, sharpened pins used for holding fabrics while sewing, attaching paper to pin boards and the like, and several types of mechanical fasteners. 

Pins are an unthreaded mechanical fastener, which are designed to be inserted through preformed holes. 

The common types of mechanical fastening pin include:

• Dowel pin: A dowel pin is simply a cylinder of solid material which is inserted through a hole. Typically, the hole has a slight interference fit so that compression of the pin and the resulting friction holds the pin firmly in place. Dowel pins also usually have a chamfered end to enable insertion. Wooden dowels are used in joinery while metal dowels are used for precisely locating mechanical components.
• Slotted pin: This is a pin formed from sheet material rolled into a partial cylinder with a chamfer at each end. The chamfer allows the pin to be forced into a hole which is smaller than the pin’s relaxed diameter. The gap in the cylinder allows the pin to compress to fit into the hole. The sprung nature of the pin then holds it securely in the hole.
• Coiled or spiral roll pin: This is similar to a slotted pin but the sheet material is coiled by more than a complete revolution. A coiled pin is therefore more heavy duty than a slotted pin
• Spring or roll pin: This is a general term for both slotted pins and coiled pins.
• Grooved pin: A grooved pin is a solid pin, typically steel, with three grooves swaged along its length, or a part of its length. This creates a pin with more elasticity than a solid dowel pin but stronger than a spring pin. It is also driven into a tight hole.
• Split pin: A pin which is bent in half so that both ends may be inserted through the same hole. Typically manufactured from a half-circular profile so that the two ends together form a circle which fits into the hole. The bent end is formed into an enlarged end and the double end can be bent outwards to prevent the pin being removed.
• Cotter: A wedge or tapered pin, which is driven into a hole. The tapered nature means that it is compressed as it is driven into the hole, causing friction which prevents it from working loose. The term ‘cotter pin’ is also sometimes used to refer to a split pin, R-clip or circle cotter, especially in the United States.

Clips

Fastening clips are excellent “hidden” clips and can be used to enable the secure fastening of interior and exterior trims and panels of rotatory shafts. With a clip fasteners, you can drastically improve the durability and strength of any structure or machine you construct using these. Metal clips are often used in the designing of machine components which require the assembly to bear with rotational movement without loosening. These clips ensure that the ergonomics you achieve with them are unparalleled. Some common types of clips are:

• E Clips are shaft mounted for rotatory assemblies. They act as the retaining ring in bores and other applications in which radial and centrifugal force is applied to the assembly. The purpose of the e clips is to restrict the loosening of the components due to the rapid rotational motion. They are inserted into grooves placed on shafts to create a shoulder that retains the assembly. These clips eliminate the need for threading, tapping or other machining operations required for traditional fasteners.
• Internal Circlips are retaining rings used for securing mechanical elements or bearings in bores and other rotating assemblies. They are mostly used in applications in which a centrifugal force is applied along the assembly's axis. The circlips are inserted into grooves and are used to create a shoulder to retain the assembly. To quickly install or remove the circlips, lugs with holes have to be used.
• External Circlips are used in assemblies where a lot of centrifugal force is applied to it. These fasteners are used to prevent the loosening of the assembly against high rotational speeds. They are used to hold rolling bearings on its shaft to facilitate the smooth movement of the bearings. To attach or remove these fasteners, lugs with special holes have to be used.

Lifting & Hanging

For lifting and hanging purposes, most commonly eyebolt or eyenuts are a mechanical fastener with a threaded shaft (or threated core similar to a normal nut) and a head forming a ring. Eyebolts/nuts are used to attach an eye to a structure, through which rope, cable or shackles can be secured. A common use is to create a lifting eye so that a crane can be attached to machinery, with special purpose lifting eyes rated for their safe working load.

• Anchor eyebolts: Eyebolts with some form of anchor bolt to enable fastening into masonry structures.
• Screw eyes (or eye screws): The are similar to an eyebolt but with a wood screw in place of a machine screw. These are used for attaching an eye to wood or plastic structures. Small screw eyes are used to hang picture frames and curtain wire.
• Ring bolt: An eyebolt with a captive ring passing through the eye of the head, effectively forming two chain links. This can reduce bending forces on an eyebolt.
• Eye nut: An eye nut is actually a nut which serves the same purpose as an eyebolt, although they are sometimes identified as eyebolts in catalogs.
• Pigtail eye bolts: These are a formed from a length of bar, similar to ordinary low strength eyebolts, but the head is bent into a helix so that it does not fully close on itself but can continue past 360 degrees. This allows the middle of a rope to be threaded into the eye without requiring access to an end.
• Roller eyebolt: These are designed to guide a rope or cable so that it can pass smoothly with minimal friction. The head is actually an assembly with four rollers retaining the rope which passes through it.