Characteristics of Butterfly Screws

A butterfly screw features a butterfly-like shape and embellishing look that makes it even more interesting. This design is ideal for usage, where the hinge is visible and more effective hardware would fluster from any piece of furniture, such as door or other product.

Replacement hinges are usually available at the home supply stores and are used for projects such as mending old furniture items or installing new cabinet doors. Such kind of fastener is also seen at salvage units, especially in cases, where people are willing to use historic hardware.

The accurate shape of a butterfly hinge usually varies from one company to other, but in most of the cases, it somewhat looks like the wings of a butterfly i.e. wings spread over from the center pin. Ornamental coats usually include a wide range of characteristics, as well as scrollwork or carved. There are even some models, which are coated in enamel to render a rich colored appearance. Such kinds of screws are designed specially to fit in properly, so they will be less visible, and accurately get placed inside the screw holes, which are typically bevelled.

The butterfly screws are also known as dovetail hinges and are mostly used for fine furniture projects. Appliances such as cabinets, boxes and other projects featuring hinged panels, doors, and similar characteristics may involve ornamental hardware, so as to prevent a jarring appearance. Depending on the pattern, such kind of rivet is made visible, whenever the project is opened or closed and can accord to the overall appearance. Do not go for bulky hinges if you’re looking for a general stainless steel finish, as it might appear out of place.

When looking for such kind of fastener, it is always necessary to pay extra attention to the screw depths and weight rating. These screws come in a wide range of sizes and pattern, from very small structures for miniature cases to heavy ones for cabinet drawers. So always be careful in choosing the correct size, as the wrong hinge may not be able to tolerate the weight, thereby causing a door or lid to fall out of plumb.

Screw depth is another necessary factor to consider; as long-sized screws could create cracks in the surface material or may penetrate all the way through.

Features and Types of Mungo Anchors

A nylon plug is a kind of wall plug or screw anchor (dowel), which is used in attaching a screw in a porous or brittle kind of material. This kind of fastener is usually made up of plastic/fiber and us used to hold a screw in place.

The nylon plug is mostly used where the surface is too thin and weak to render a strong grip for the screw threads. This kind of fastener is popularly known as Mungo anchors. The brand is quite popular in the market and most of the customers recognize the dowel by this name. The Mungo is a leading fastener manufacturing company, producing all sorts of screws and fasteners, even including the wall plugs.

The Mungo nylon plugs are available in a variety of materials, types and prices and are used for both heavy-duty as well as light-weighed applications.

Their functionality is similar to that of a nut, which comes along-with a bolt. The nuts prevent the screws from releasing out of the drilled holes. The nylon plugs, unlike the nuts can be placed into the wall and can be employed from outside of the wall or any other surface.

The Mungo anchors are available in various forms, but the most commonly used type is the tapered tube, which is made up of soft material, such as plastic. This particular type is secured loosely into the pre-drilled hole first and then a screw is inserted into it at the center.

While the screwing action of the rivet chunks the plug firmly into the hole, the soft material assures fastening to the masonry. Even these anchors are used to attach two objects in situations, where nails, adhesive and other fasteners do not work. These plugs also endure different levels of strength and can be used on various types of surfaces.

Check-out this video

The Mungo anchors are mostly used for hanging items on walls, and hence, they are also known as wall anchors or wall plugs. The drywall screws, which are used in modern day housing often breaks up too easily. The use of a screw anchor enables a stronger grip for the threads.

Sometimes, these nylon pieces are also known as “expansion anchors”, as these types of plugs render opposite-surface pressure that helps secure the screw in place.

When the nylon plug is inserted into the surface, a part of it protrudes out from the drywall or any other surface, where the screwing is done. This exposed portion expands and becomes longer than the drilled hole. This kind of feature prevents the anchor from getting back to the hole.


Earlier, fixing was done on a masonry wall by cutting a groove into a channel into a soft mortar joint and by hitting on an unpolished wooden plug. This kind of process was time consuming and always required a large hole, thereby leading to patching work thereafter. Moreover, the location of the holes were only confined to the mortar joints.

The nylon plug was designed in 1911 by Joseph Rawlings and became popular as Rawplug soon after the First World War. These plugs were at that time thick fiber tubes and were made up of parallel strings fixed with glue.

The most current design was designed by Arthur Fischer in 1958.

The Mungo anchors are widely available online. The best way to get those fasteners at cheap rates is by buying them online.

Other types of nylon plugs, designed especially for hollow walls, include toggle bolts and molly bolts. 

Different Types of Turnbuckles

A turnbuckle is a 3-piece metal coupling device, specially designed to alter the applied tension slowly without spinning the cable/rope to which it is attached. This kind of fastener is enabled with an elongated or rectangular body and features screw holes threaded at opposite ends at the two-threaded inserts.

STB,STJ,STH and STE TurnBuckles

The threaded regions of the turnbuckle either feature a hook or screw-eye at the non-threaded end. When these inserts are threaded into the device and the buckle is rotated, the screws eject out of the body, thereby releasing tension. And when it is turned in anti-clockwise direction, the screws on the other hand are driven towards the center, thereby increasing tension.

Turnbuckle Thread View

Turnbuckles are usually comprised of internal screw threads along-with a long sleeve at both ends, so that they can be pulled together or pushed farther apart by twisting the central nut. The eye turnbuckles are also known as bottle screws and are used to fasten wires, cables, ropes, or shafts, which are either attached to an anchor point or to other cables, including ropes and shafts.

Different types of turnbuckles

Eye Turnbuckles

Eye Turnbuckle

These types of rivets feature a circular and enclosed connector on one or either sides. This circular part is known as eye and eye, hook and eye or jaw and eye. The eye portion of the buckle is made up of a shaft, featuring an eye outside and a threaded shaft inside, which blends with the turnbuckle’s central nut.

The eye shape of this rivet is ideal for those devices, whose anchor point is enabled with a flexible shaft that can be secured into the eye. It is preferable at areas, where there is a possibility of the anchor point to slip out of an open hook.

Hook Turnbuckles

Hook TurnBuckle

These types of fasteners feature a hook at both the ends and are known as hook and hook, hook and jaw or hook and eye. The hook portion comprises of a shaft along-with an open hook on the outer end and a threaded shaft on the inner part, which blends with the turnbuckle’s central nut. The hook shape is is ideal for those areas, where there is easy and quick attachment and where the anchor point does not merely slip out the opening of the hook.

Jaw Turnbuckles

Jaw Turnbuckle

These types of turnbuckles are enabled with a jaw and a u-shaped connector along-with a bolt connecting the ends of the U. These are also known as jaw and jaw, hook and jaw, or jaw and eye. The jaw portion features a shaft along-with a jaw outside and a threaded shaft inside, which couples with the turnbuckle’s central nut. The jaw end is is ideal for those devices, whose anchor point is fixed and where there is a possibility of the anchor point to slip out of an open hook.

Stub End Turnbuckles

Stub end Turnbuckle

These are also known as stub and stub and are made up of two threaded shafts, which couple with the turnbuckle’s central nut. These rivets are used at places, where a connector is not required for an anchor point and in areas, where the turnbuckle is used to push apart objects on either end.

All Types of Turnbuckles

These are the primary types of turnbuckles used in the hardware industry. However, if you go online then you’ll come across various other types as well, suiting every industry requirement. You can visit here to know more about these fasteners.

Resources :

1. Turnbuckle.

2. Safety Methods for Turnbucles.

Various Types of Cap Screws

Cap screws are available in slotted flat head, hex head, high round socket head and low round socket head types. These are also available in various grades, including 5 & 8, zinc plated and fine threaded patterns.

They are also available in regular steel as well as in stainless steel, thereby giving the users an ample amount of choice. They can go for a particular pattern and design, which best suits their jobs and requirements. As these fasteners are available in various designs, you will also require specific kind of drivers to fasten and loosen them, such as slotted, hex, Phillips and hex key socket drives.

We even offer other related accessories, including screw nuts, washers, lock nuts and lock washers. Apart from all these, we even offer items on almost all kinds of fasteners, ranging from deck screws, anchor bolts, dowel pins, elevator bolts, flange bolts, blind rivets and much more in the list. All you need is to keep on browsing our extensive range of products to understand the vastness of our offerings. However you can simply type in the product item in the search box, which would then lead you directly to the landing page.

You can settle down on any particular item, which is best suitable for your job. The industrial fasteners are available with either coarse or fine threads. The materials include iron, steel and stainless steel and finishes mat be galvanized, zinc plated, zinc or black phosphate, determining the material of each rivet.

These types of metal pieces are usually ordered in bulk amounts from our store and our potential clients usually belong to various manufacturing sectors. These fasteners are available in various sizes, ranging from 6.35 till 76.20 mm in diameter. These type rivets are quite similar to hex bolts.

In certain countries, these are also referred as bolts, but as per the US Govt. document; Distinguishing Bolts from Screws, these fasteners have been classified under the screws category, mainly because of their higher tolerance capacity.

However, the term cap screws are referred to various things at various times and places. In US, these are mostly defined by ASME B18.6.2 and ASME B18.3. Earlier, these metal pieces were used in places, where nuts could not be applied. Today, they are used on much wider scale, as they feature advanced properties thereby broadening their usability.

Significance of Bone Screws

There are very few fasteners, which work beyond the hardware industry and household appliances. The fasteners, such as bone screws, play a major role in orthopaedic world. So, before getting deeper, let’s know the basic definition of such kind of rivet.

What is a bone screw?

It is a specialized kind of screw designed for use in orthopaedic surgery. It is used to assist in the healing of a fractured bone. It is a special kind of fastener, which is made from a non-sensile material and is implanted into the fractured bone, so as to stop the segments from moving around. This type of rivets fastens the broken segments of the bone with one another, thereby enabling it to heal properly. They can be later removed, allowing the bone to fuse back to its original form.

When the injured cartilages are required to be fused together, a bone screw is implanted into the fractured area either temporarily or permanently, depending upon the severity and age of the case. In cases of elderly people, it’s quite difficult for broken ligaments to heal up naturally. Therefore, they have to bear those metal pieces in their bodies for the rest of their lives.

Here’s a video explaining the screw imlantation method. Do have a look!

Considering on the severity and location of the injured part, a patient is usually given local anaesthesia for implanting such fastener. The surgeon cuts off the skin of the fractured area. After repositioning the displaced bone at its accurate position, the screws are then inserted into the bone for a predetermined time-period. When the healing process is completed, the screws are then either left in place or removed.

The orthopaedic specialists may use one of a variety of methods, including these rivets for in their distinct cases. Typically, such metal piece is inculcated into the bone directly across the damaged area to fuse the torn pieces together. The rivet is further driven through the bone with a specialized type of tool, much like a drill. This kind of special drill is used to create a pre-drilled hole in the spot, before installing the screw.

US Navy doctors perform an open reduction internal fixation operation on the femur.

Bone screws are available in varied range of sizes and materials and are used distinctively in cases of different bone repairs. The recent advancement is medical research has conceived a wider selection of materials and options for patients requiring particular type of fasteners for their treatment.

Earlier such metal pieces were made from titanium. And a surgeon had to go through two different steps so as to implant the screw into the damaged area and then to surgically remove it later. This process was quite painful and time-consuming and the holes created from the screws never used to heal. However, these days, researchers have greatly improved the technique and have come up with an idea that screws can be made from a certain material that grows into the implant and eliminates the holes in the bone caused by the screws. This recently invented material is known as biodegrade and is now quite abuzz.

The procedure and tools used also depend upon the kind of fracture and which bone is actually broken. As with any other surgical method, there are certain risks and so also benefits involved to inserting and removal of these metal objects. Based on the scale of damage and the overall health of the patient, the doctor determines the best course of action for bone repair accordingly.

Different Types of Framing Screws Used in Construction Industry

Framing a drywall patch area may require a screw primer. Strength has to do very little in such a case, as no serious loads will be put on the framing screws. So, any fastener that goes through the 2 x 4 dimension of the existing framing can work.

Framing Screws

Since a 2×4 stock is only 1.5 inches thick, so you’ll need a screw of at least 1/2 inch longer than the stock. A really long screw can be a disadvantage, as it will take longer to drive, thereby incurring more friction. A thick screw is however recommended for framing in a drywall patch area. A 2 or 2.5-inch screw is a suitable option, as the user will be drilling at a particular angle through the wood.

Framing screws, which are used for installing a gypsum board usually feature flat/concave heads and are thin at the rim. Fasteners with heads, having a diameter ranging between 1/4 inch and 5/16 inch should be used, so as to provide sufficient holding capacity without have to drilling the face paper when the screw is indented. Use of casing nails should be avoided, as their heads are too small as compared to their shanks; consequently these nails can easily cut into the face paper.

gypsum board Installation with framing screw

Large-size screw heads can easily cut the paper surface if the rivet is drilled incorrectly at a slight angle. So, screws long enough to go through the wallboard layers should be used. Plus, in supporting construction, they also render adequate holding capacity. Always make sure that the diameter for screw penetration into framing members should be 7/8 -inch for smooth shank nails and only ¾ -inch for annular ringed nails. This kind of specification provides more withdrawal resistance.

In case of a gypsum board, the drywall screw is the most commonly used type of fastener. It is used for attaching gypsum board to either a framing wall or an existing gypsum board. Drywall screws are enabled with Phillips’ heads, specially designed to conveniently fit into the tip of a powered drywall screwdriver.

Collated Drywall Screws

These types of rivets secure the board firmly to the supports without affecting the board. They reduce surface defects occurred due to loosen boards and shrunk lumber. The specially contoured heads of such framing screws, when correctly driven, create depression-free uniform ragged edges. Proper installation of the rivet on the power screwdriver enables accurate countersinking of the drywall screw head with joint compound for a proper fastener concealment.

Types and Sizes of Drywall Screws

The above images used for the three basic types of drywall screws; Type S for light gauge steel studs, Type W for wood and Type G for solid gypsum construction. The image also features a sample of a Type S-12 screw, which is used for fastening wallboard to heavier gauge steel framing.

Type S gypsum drywall screws are used for attaching gypsum board to furring/steel studs. These rivets are usually self-drilling by nature, featuring a self-tapping thread and a hardened drill point for inserting the metal with little pressure. This kind of fastener caters to easy installation, which is necessary, as steel studs often are flexible and tend to bend away from the screws.

Type S gypsum Drywall Screw

Type W gypsum drywall screws are used for attaching gypsum board to wood framing. The diamond-shaped points of these rivets enable effective drilling action through both gypsum as well as wood, and their specially designed thread renders fast penetration, thereby enhancing the holding capacity. Such  screws are installed into the supporting construction, which is at least 5/8 -inch thick.

Type G gypsum drywall screws are used for attaching gypsum board to gypsum backing boards and are quite similar to type W screws. However, they feature a deeper special thread design and are usually 1-½ inch in length. These drywall screws are installed into the supporting board at a diameter of at least ½ -inch of the threaded portion. These screws should not be used to attach wallboard to 3/8-inch backing board, as the backing board is not suitable to support a face layer using screws alone.

Pan Phillips Framing Screw Specifications

There are various stainless steel screws available in the market for framing. Stainless steel is ideal for applications, such as exterior decking, which is driven into pressure treated wood. However, stainless steel is comparatively soft and one can easily tear off the head of a stainless deck screw if additional torque is applied over it. So, in such a case, basic steel screw is suggested, ideal for general construction application.

Anchor Bolts: Essential for Construction Job

Anchor bolts are a much needed essential for any kind of construction job. These are mostly needed to fasten certain objects to the concrete wall or surface, so as to enhance the durability of the foundation. With such kind of fastener, the concrete becomes earthquake resistant and also can sustain any kind of adverse environmental conditions.

These are the most sought-after rivets in the hardware industry, as they are used in various purposes. These are available in various designs in the market, most of which are patented by specific companies. However, these possess a definite threading pattern till the end, to which a washer and nut are attached for the outer load.

The anchor bolts are extensively used in various types of construction projects, ranging from constructing dams to the standard building architecture and also in nuclear power plants. These types of rivets are also used to rigidly affix the tucked in plates into a firm concrete foundation, while using any basic steel element.

These are available in various designs, including wedge bolts, which are ideal for interior usage; galvanized wedge bolts, enabling best corrosion resistance; strike bolts, which are ideal for solid concrete set-ups for both medium and heavy loads; sleeve bolts, which best work for heavy duty anchors; lag shield bolts, which are used for both light as well as heavy loads managing light-weight and fluctuating loads to be fastened in the concrete surface; leadwood screw anchors, which are ideal for removing fixtures; double expansion affixes, which are ideal for anchoring into block base material say, bricks; hurricane shutter type are enabled with shutter embed anchors to enhance good fastening ability.

Among all the patterns, the simplest one is the cast-in place affix. Almost all the above mentioned designs feature standard bolt along-with a hexagonal head, which is helpful in casting in the wet concrete, before it sets.  These are also the most strongest of all other anchor bolts and they are ideal for heavy duty machines, which are clambered upon poured concrete floors.

Today, various types of tools are available in the market to assist in managing and in setting these bolts to fit well in the concrete surface.

Types and Features of Left Hand Threaded Bolts

Fasteners are used in various hardware jobs. Almost every kind of fixing job requires screws, bolts and anchors. These are now extensively used, ranging from fastening two wooden panels to fixing heavy duty specialized stainless steel bolts into extreme surfaces such as in the building of oil rigs. The left hand threaded bolts are one of the most common types of screws used in the hardware industry.

male and female external threaded bolts

These bolts are usually made up of plain steel and are fully threaded. These bolts feature a left-hand thread, unlike regular fasteners which are turned right while tightening. These all-thread types are used along-with nuts and are used for most common fastening procedure, ranging from anchor to a through bolt.

These are quite useful, as they are also used as ultra-long bolts. They also act as superb replacements in situations when a correct length of bolt cannot be established, as these fasteners can be easily cut into desirable lengths.

Unified Thread markings

These stud bolts are available in three common designs in the market, which include the double end, tap end and the continuous head.

The double end is most likely the continuous threads and uses two nuts for fixation. Each end is threaded by a smooth shank and both ends feature flat ends. The tap end features a smooth shank, which separates the thread and one end of the thread is longer than the other end.

Thread diameter

While one end is employed with a nut, the other end is screwed into a tapped hole. The continuous thread features a continuous end throughout the body with flat ends.

Unlike screws, which are tightened with the help of a screw driver, you will require a wrench to fasten a left hand threaded bolt to any surface. If you are looking to do any hardware job all by yourself then make sure to have required tools to fasten such bolts.

Bolt and screw head typical forms

The Internet can be your best guide to understand the types and functionality of such hardware supplies.

Top 15 Questions on Bolts Answered

Here are some of the most sought-after questions on bolts answered. Have a read!

1. What size of i-beam and anchor bolts used for basement wall?

The I beam dimension depends upon the height of the backfill, the wall thickness, wall construction, the soil type, quantity of bowing and few other abstractions. Most i-beams feature a 6″ beam as per standard rule. Spacing also varies as dimensions and so is the anchoring, if you have a sub-floor/thin floor interior drain tile installed. Connection at the top changes provided the wall is load bearing. You can take the help of a structural engineer, who can lay out a comprehensive repair plan for you, as this wall stabilization should be fixed by someone who can see all the issues with the site.

For home construction, a certain code requirement is followed that states – exterior walls are fastened to the foundation walls to sustain lateral movement, which is usually seen in an earthquake

The horizontal 2×4 at the base of the exterior wall rests on the foundation wall through a sill plate. This plate is bolted to the foundation wall by using anchor bolts, so as to keep the walls static. The spacing of anchor bolts in the sill plate should be above 6 feet at the center and within 12 inches of any sill plate joints.

You can check with your building department if you’re not able to place anchor bolts within appropriate spacing. They can suggest you in taking proper action or local requirements before proceeding further. There are distinct building code requirements available w.r.t bolt diameter, length and spacing for new construction versus retrofit construction. The length of the anchor bolt also depends upon the strength of the concrete foundation wall, the thickness of the sill plate and required holding values. However it usually ranges between 3.5” and 6.25” of embedment into the concrete. It is always recommended to check-out for your local building codes, building official or with an architect to consider the size of anchor needed.

Did you know? 

Anchor bolts in concrete construction can be either cast in place or post-installed.

2. What is the torque for pan bolts on gm 4l80-e?

The torque of pan bolts required for gm 4l80-e is 24 NM and 18 ft. lbs.

The bolt size of a 4l80e transmission pan is 13 mm

3. What pressure can grade 8 bolts take?

Grade 8 bolts, which are also known as hex head cap screws are one of the most durable hardware supplies and are mostly used in aerospace, military and marine related applications, where sturdy load bearing pressure and high stress are hugely required. These fasteners are well-proportioned and are designed to bear high tolerance, thereby ensuring proper loading when enabled into a pre-drilled hole. These rivets feature the highest strength of standard cap screw series and are usually made up of alloy steel.

The tensile strength of a grade 8 bolt is 150,000 pounds per square inch. It is the maximum strength that a part can carry without breaking.

4. How to remove stuck lower strut bolts?

This might prove to be a lengthy step if you’re not well-equipped with necessary supplies. Everything you need for this job can be found at the Mutual Screw and Supply web store. You can even call them to inquire about what you would need for this job. And it’s always wise to fetch the extra parts, which may need to be replaced before you begin this task. The last thing you would like to do is visit a physical store in your neighborhood. So, it’s better to go online to fetch for your bearings.

Few things to consider before you kick-off
Struts should always be changed in pairs. To ensure safety, you should never outplace one strut without the other one. Check-out for the top & end parts, to see if there’s any odd bolt for which you would require a different tool. You can spray some penetrating fluid on those stubborn bolts and allow them to be soaked in.
Be organized while removing the parts. Always keep similar parts together at one definite place.
Don’t work with a Philips driver, when your job actually calls for flat.
Steps to remove struts
5. Why bolts get loose?
Click here to get a detailed answer along-with a video that shows this in action.
6. How do you replace the concrete that holds the closet bolts?
Replacing the concrete from the closet bolts can prove to be expensive, if you’re taking the help of a professional plumber and you can always cut down on this expense by volunteering for this job. The concrete (toilet flange) is the connection to the drain pipe under the commode, which enables proper flow of water from the toilet to the sewage system. If it is damaged then water can leak underneath thereby causing wet floor, foul smell and floor damage.
  1. Cut down the water supply by using cut-off valve
  2. Open up the toilet reservoir and allow complete draining of the water and use a cup to remove the left-over water
  3. Place a towel around the sink, at the point where water supply line is connected to the toilet
  4. Now remove the water supply line and also the floor bolts with a suitable wrench
  5. Remove the bolts carefully from each side and lift the toilet evenly
  6. Now the bolts from the old flange should be removed and the area should be cleaned, so that no wax or build-up material is left
  7. The old caulk should be removed now. You can use your hand and if not then go for a razor knife
  8. Now replace the commode and bolt it down and put back the caulk at the base. Now reconnect the water supply line and do a test flush to ensure the sealing is good
7. How to get rusted carriage bolts ou

Why bolts get loose?

Joints like racks and mudguards can remain maintenance-free even after running for ten thousand plus miles, yet there are certain bikes, which require frequent tightening of bolts. So, in this edition, we are going to discuss why do some rivets stay tight while other bolts get loosen so fast?

Well, if you think bit deeper then we can realize the concept behind this is quite simple. Frequent vibrations of the bike’s parts enable the nuts and bolts to loosen. (At the end of this post, we’ve attached a video which shows this in action).

The more the parts vibrate, the faster the bolts get detached. A major advantage of using a bolted joint other than riveted/welded joints is that it can be easily dismantled. However, this advantage can even cause trouble at times. Such accidental loosening, which is also known as vibrational loosening has been widely mistaken by the engineers. It is always important for the manufacturers to be alert about this mechanism.

Apart from the known factor that bolt detaching is caused due to vibration, we should also consider that the actual reason is side sliding of the fastener head relative to the joint, thereby resulting in relative motion in the threads. If this phenomenon does not occur then no matter how often the joint is subjected to severe vibration, loosening can be avoided.

Sometimes, burnout also results in self-detaching, thereby reducing the clamp force implied on the joint. Eventually, joint slips occur, which further leads the rivets to bending loads. The nuts will then rotate loose, as soon as the relative motion starts occurring between the male and the female threads. This motion then sooner or later breaks off the friction grip and instead, creates an off-torque. This off-torque makes the fastener get slowly detached.

The key to preventing self-loosening of bolts is by ensuring that

  1. There is sufficient clamp force available on the joint interface, so as to reduce relative motion between the bolt head and the joint.
  2. The joint should be designed as such to enable proper embedding and stress relaxation.
  3. You’ve proper thread locking devices, such as flanged fasteners or torque prevailing fasteners.
  4. The loosening of bolts is just one plain aspect of the bolted joint design, which the manufacturer should consider during the design process. And even if threads are firmly hold together by adhesive, this kind of situation cannot be avoided, if the bolt preload is inefficient in preventing the joint movement.

Here’s how to avoid this:

  1. Do not use the same bolt to fasten several things.
  2. The more ‘layers’ you have, the more motion occurs, thus the bolt gets detached quickly. This is common in the case of the front racks, which are attached to the cantilever brakes.
  3. Always remember than even simple washers can increase the risk of fasteners getting disconnected. Don’t go for spacers either, as they are worse.
  4. All the joints should be designed as such that rivets won’t be able to rotate. For instance, if the rack below is attached to the fork crown along-with straight tubes, which are alienated to the vibrations of the rack then in such a case, due to the curving of the tubes, each vibration would lead the bolt to loose gradually.

Applying state-of-the-art analytical method to stop vibrational loosening of threaded fasteners can be difficult. However, these days technology has much developed and programmers have come up with designs, which help engineers fix such issues.