Category: Bolts

Different Types of Bolts

Different types of bolts are available online, so as to fit into various industry requirements. Following are the most commonly used types of bolts, used in various applications and sectors. Do have a look!

Countersunk Bolts parts definition

#Anchor Bolts

Anchor bolts are used to fasten various kinds of  objects or structures to concrete. These bolts are available in various designs, which suitably fit into almost every industry requirement. These types of rivets are enabled with a threaded end, to which a nut and washer are fastened for the external load.

Anchor Bolt

These fasteners are extensively used in all sorts of fields, ranging from nuclear power plants and standard buildings to dams and home renovations. They help in firmly fixing implanted plates to a concrete foundation, featuring a structural steel element.

One of the simplest forms is the cast-in-place anchor, which is the strongest type of fastener. It features a standard bolt with a hexagonal head, which is fixed in a wet concrete before it sets. It is used in heavy-duty machines mounted on poured concrete floors.

Cast in place Anchors

Features

  • Rust-resistance
  • Sturdiness
  • High consistency

Other commonly used designs features a bent bolt along-with a hook at the end. Click here to know more about these bolts.

#Roof Bolts

A roof bolt usually comprises of a shaft for injection into a pre-drilled hole, mostly in a mine roof.

Schematic Diagram of Roof Bolt

The head of such bolts is counter-balanced with respect to the longitudinal axis of the shaft so that when the rivet is rotated by means of its head, the shaft creates a circle of greater diameter an offset between 0.08″ and 0.25″. Usually, the counterbalance should be between 0.10 and 0.16 inches.

This kind of method is implemented, so that at least 90% of the bolts produced so far have their head central axis equipoised with the longitudinal axis of the shaft by 0.08″.

Roof Bolt

A typical mechanical roofing bolt incorporates a 3-leaf mechanical expansion shell.

While installing, the expansion shell gets activated by employing torque over the nut end, thereby forcing the shell to expand and get engaged in the hole.

Anchor Bolt with a Threaded Rod

Benefits

  • Enables a versatile system for rock reinforcements
  • Renders immediate support for installing 300 mm from the face
  • Easy installation and production time saving
  • Cost effective support method
  • Less prone to blast damage on the face
  • Easily gets along-with mechanical equipment

#Hex Socket Bolts

Hex Socket bolts

These are six-sided bolts, specially designed to meet various industry standards. The hex socket feature is shown in all SAE hex bolts, ASTM A307 grade A bolts. There are heavy hex socket bolts available in the market, which are required for A307 grade B, A325 and A490, requiring a hex pattern.

These are used in various applications, including wood, steel and construction supplies required for bridges, docks, buildings and highway structures. These rivets are also known as headed anchor bolts.

Dimensions of Hex Bolts

Features

  • Standard: DIN912
  • Size: M6-M64
  • Material: carbon steel,stainless steel
  • Surface treatment: self color, zinc plated, H.D.G

#Elevator Bolts

Elevator Bolts

These bolts were introduced in mid-18th century. In those days, these were used to fasten the lift buckets with a belt, so that the grains could be lifted to be stored in the vertical grain cabinets of the lift. Today, these rivets are rather used in broad applications, which are altered to transporter systems.

Features

Features of Elevator bolts

  • Material: General Carbon Steel, Carbon Steel with zinc plated, Stainless Steel
  • Intensity of Bolt :  Class 4-8
  • Model: Standard Bolt, Flat Countersunk Bolt, Fang Bolt (Tooth Bolt), Belt Bolt.
  • Standard: GB, ISO, ANSI, DIN, BSW, JIS
  • Dimension: M3-M22
  • Length: 10 mm-600 mm
  • Grade: 4.8, 6.8, 8.8, 10.9, 12.9

Visit here to know more about these bolts.

#T-Bolts

T Bolts

T-bolts enable a durable and convenient connection. These fasteners swivel into the required position, so that they can be easily fixed soon after a structure is assembled. These are used in building, instruments, automobiles, furniture etc. These rivets are available in aluminum, brass, carbon steel, stainless steel and copper. These are also available in zinc plate, black, chrome plate, HDG etc.

T Bolt Types

Features

  • These can be installed anywhere along the profile’s T-slot and rotates into position
  • Their grooves “bite” into proile to lock the T-bolt into position, offering ESD
  • protection and resistance to vibration
  • Huge contact surface improves gripping of the str

History of Nuts and Bolts Industry in America

People, who are involved in hardware supply industry, would always be curious to know about the history behind the establishment of supplies, they are dealing with. Well, the history of nuts and bolts industry in America is quite interesting.

What excites more is the fact that in earlier days, when technology was still in a nascent stage, the hardware industry was still active and people managed to get their jobs done without feeling the need of some inventions or so. This edition highlights about the history behind the establishment of two most commonly used fasteners in the world – nuts and bolts.

For something as small as this kind of fastener, it has rather got a huge job to do and is available in various patterns. In America, when the people most conveyed through horse-drawn carts, such types of fasteners were the most essential requirement to manufacture such kind of transportation. The carriage era actually signified the aristocracy of the Americans and the upper class people were usually seen commuting in carts. Even in Hollywood movies, which are based on 18th century or early 19th century eras, say Titanic, Shanghai Knights etc. the horse-drawn carts had a significant role.

With such an extensive use of these transport options, the supplies required in their manufacturing were also in much demand, especially the nuts and bolts.

You can admire their applications at the Carriage Museum of America, where the fasteners, such as screws and nuts belonging to 18th century are showcased exclusively. The images show the masterly works by the then blacksmiths, who had skilfully used the rivets keeping in mind the exquisiteness of the carts.

Since it’s a carriage museum, so most of the attention would go towards the hackneys, but if you look deeper, you would be amazed to see the masterly craftsmanship lying behind the beauty of these wagons. The nuts used in these carts are comparatively flatter and square-shaped than modern day fasteners. In those days, less care was taken to embellish the flush of the bolts, unlike modern nuts, which are left with a little or no burr on the end of the bolt.

As per the historian, W.R. Wilbur, the first machinery application to build bolts and screws was invented by Besson in 1568 in France. A century later, this device was further developed by Hindley of York, England, which was continued to be used for many years later on.

In America, these fasteners were originated by Micah Rugg, a small country blacksmith, in the town of Marion, Southington Township, Connecticut in 1818. The carriage bolts, thus came into being, which then went on to become a significant requirement in the manufacturing of these transport devices.

“It was several years before power was applied to perform this operation, and when that was done a boy could accomplish more and with greater ease than half-a-dozen men could previously with the old fixtures. It was about this time that the turned head was introduced, and, if we are not mistaken, it was to circumvent the patented process of the drop.”

Carriage bolts are not intended to be driven, therefore you need not have to insert the bolts in a pre-drilled hole. There’s no need of using any tool even to fasten it. These days, this historic rivet is widely used and can be seen in automobiles, railways, bridges etc.

Blind Rivets: Replacing the Traditional Clinch Bolts

A rivet is usually a kind of solid mechanical permanent fastener. It comprises of a smooth barrel-shaped rod with a head at one end and the opposite end is known as ‘buck-tail’. It is available in various types, designed specially to meet various industry requirements and accessibility. These include solid round head, structural steel type, semi-tubular, blind rivets, drive, flush and friction-lock type to name a few.

Blind Rivets

During installation, the affix is inserted into an already drilled or punched hole and its tail is bucked or deformed, so that it stretches up to 1.5 times than the original shaft diameter, thereby helping the rivet be in place. You can distinguish the two ends of the fastener by yourself. While the original head is known as the factory head, the deformed part is known as the buck-tail or shop head.

The head, located on the each end of an installed bolt, efficiently supports tension loads, which are parallel to the axis of the shaft. However, it is more capable of holding shear loads, which are vertical to the axis of the shaft. Fasteners like rivets and bolts are best suited for tension applications.

Even fasteners used in traditional wooden boat building, which is one of the oldest fields of engineering, such as clinch bolts and copper nails also work on the same principle as the rivets do. However, the rivets always have advanced features and better usability and so are now highly in demand.

 

The blind rivets, which are also known as pop rivets, are tubular in shape and are enabled with an arbor (mandrel) at the center. The assembly of this metal piece is inserted into a pre-drilled hole by a specially designed device, which is capable of drawing the arbor into the rivet.

Such kinds of fasteners feature non-locking arbors and are not ideal for fixing critical structure joints, as they may fall out due to the external vibration. In this way, a hollow rivet will be left out, featuring a less low load carrying capacity.

In addition to, they even become more prone to get spoiled because of the corrosion. The blind rivets, unlike other patterns can be easily inserted into a joint from only one side of the structure and is rather ‘blind’ at the other end.

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.

         [youtube:nZek9brVZI8]

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.
Methods
 
  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

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.

Salient Features of Stainless Steel Carriage Bolts

Nuts and bolts probably share the same chemistry as that of salt and pepper. While nuts are hardware fasteners, featuring threaded holes, the stainless steel carriage bolts are fasteners, featuring round and flat heads without any thread. These are tightened by a rench onto a surface and the process is completed by fastening the bolt at the other end. The bolts are available in various types in the market.

Such type of fastener is usually found in wooden chairs or couch, which hold two separate wooden pieces. Not only in the furniture, but these fasteners are widely used in iron and steel industries as well. The heavy duty screws and bolts are specially designed to withstand heavy weights and offer safety and durability. The bolts are available in three primary designs and the carriage type is one of them.

These fasteners are used in holding individual pieces intact and are available with washers and nuts. This particular stainless steel type is different from others because of its thread that is continuous on its entire length. You need to consider the head of such bolts, so as to understand their functionality i.e. if they are used for masonry, machines etc.

However, the stainless steel carriage bolts usually feature a round head and square collar. If you’re thinking of tightening this item in a place then you’ll definitely require an appropriate wrench, suitable for your chosen bolt. The collar of the bolt fits into the pre-drilled hole and in special cases; it is twisted into a rather fragile surface say wood.

This is done as the collar of such fasteners are square in shape, which prevent them from turning while the installing process. Besides, the threads are coarse, so you need to consider their diameter before buying these items.

The stainless steel carriage bolts are available in diameter ranging from 3/4 to 3/16 inches and in lengths ranging from 1/2 to 10 inches. You can go online to check-out the varieties and can settle for a particular model, which best suits your job requirement.

Various Uses of Shoulder Bolts

With the diverse industrial requirements, the hardware supplies are now-a-days available in wide varieties. The hardware market is replete with various types of nuts and bolts. All you need is to go online and fetch for your desired item, which best suits your work.

Shoulder Bolts

There are some fasteners, which feature diverse applications, like the shoulder screws. These rivets are used in various applications, even in areas which require rotation and locking of screws. These rivets are also known as shoulder bolts. The primary difference between such screws and other types of rivets lies heavily in threading. Unlike regular screws, the ridges of these fasteners, which wind up the shaft, finish off as soon as the rivet is turned into the hole.

In regular screws, the threading is present across the entire body, but in shoulder bolts, the threading ends few distance from the head, thus leaving behind a smooth square/round shaped shaft between the head and the threading. Their shaft is usually larger than the threads. And because of this unique design of theirs, these fasteners are able to meet diverse requirements. For instance, these rivets are used in mechanical as well as in automotive fields, as their cylindrical structures make good fastening objects for pulleys, moving parts and linkages. The round heads enable these screws to be suitable for the above mentioned applications, as they allow easy rotation just like a pin linkage.

These rivets are also available in square shoulders, as it is with the case of the round head wooden bolt. They are quite useful as they easily resist the rotation, thereby behaving as a durable fastener. The head wooden bolt is ideal for furniture, as its square shoulder can efficiently resist movement, thereby enabling it to get locked inside the furniture. Furthermore, it features a smooth round-shaped head without any slots for a wrench or screwdriver. In this case, the bolt is tightened with a nut, which is attached onto the threaded end. The application can be seen in children’s playground in the wooden play structures.

The shoulder bolts are used for varied purposes. Thus, depending upon the type of your job, you should go for the particular pattern of such fasteners.

Multiple Uses of Flange Bolts

The company, Mutual Screw and Supply has gone a long way in establishing a brand of excellence and the best available artisanship in the industry since its establishment in 1947. Presently the company is selling its products all over US and parts of Canada & even overseas.

Today this company has become a well-known hardware supplier in the world of online marketing. We, at Mutual Screw are specialized in the manufacturing of flange bolts and various other kinds of fasteners, including all types of screws, hardware kit and much more.

A flange bolt is different from a standard bolt. Unlike other bolts, it features a broad surface area beneath the head to render a smooth distribution of securing pressure. This wide space acts as a washer, thereby eliminating the requirement to look for an additional spare for application of such bolts.

Flange bolts are available in diverse range in our store in terms of sizes, configuration and strength. Like other rivets available in the market, these bolts are equally capable of undergoing various applications which require them.

Our specially designed flange bolts are enabled with special anti-rotational “teeth” features, which are designed to “bite” or dig into any hardened material necessary for fastening purposes. These are quite similar to the locking rings, which one might have seen on a milk jug or soda bottle.

Theteeth’ present on the these rivets can be turned backward, but however, requires more force. This kind of specification is what makes a flange bolt anesthetically and strategically different from a common bolt.

To facilitate more, we’ve made an essential addition to our flange bolts are the flange nuts. While these look like the ordinary nuts, one portion of the flange nut is wider than the other only to ensure equal pressure distribution. Both of these metal pieces work together, thereby reducing costs by eliminating the need for buying separate washers.

We also make sure that Always remember that proper torque on a flange bolt-nut combination ensures that the rivets never get loosen by themselves, except for the external force such as a mechanic, which can loosen these types of flange bolts.

Our specially designed fasteners are suitable with any kind of flange system. The strength ratings along-with sizes and grades can be changed depending upon the type of application. We offer sizes as per the Society of Automotive Engineering (SAE) measurements, such as 1/4 inch and 1/2 inch. Besides, we also deal with metric measurements, such as 8 mm and 10 mm.

Our vast range of products can easily fit in with anybody’s requirement, no matter whether it’s for personal or industrial use. Our ranges of products are designed with high quality and modern techniques. Keep reading to know more about this particular product!

The flange bolts are usually used in vehicle frames, especially in trucks and anywhere a head bolt is required. They feature a nozzle, thereby speeding the assembly while eliminating the washer. They render four times the bearing area than of a standard hex screw.

These types of fasteners are produced from high carbon alloy steel, which help them manage with the 150,000 PSI of minimal tensile strength. These fasteners are available in diameters ranging between 3/4″ and 3/8″ and lengths up to 31/2″, measured from the base of the head.

These particular fasteners are used with Grade G Style Lock Nuts, so as to develop a sturdy bolt system that would not only render a wider area, but also resist loosening. These rivets are also known as hex flange screws, hex frame flange bolts and hex washer frame bolts.

The 12 point flange bolts, which are also known as counter bore cap screws, are used in aircraft devices and in various automotive applications. Their major advantage is that they can be easily installed, by simply using a 12 point socket and well-ventilated impact wrench. These are also used in bikes along with wrenched decorative heads, thereby enhancing the look.

While going for a nut with flange bolt, it’s always important to check-out of the grades of the nuts and bolts are same. You should always go through the instructions if you are not much aware about the application.

Some Prevailing Myths about Grade 5 Bolts

Grade 5 bolts are usually manufactured from suppressed and tampered medium carbon steel. They are usually used when greater tensile strength is required during a process. It is processed through yield-to-tensile ratio, which is the lowest among all the heat-treated steels.

These bolts are available in both domestic and commercial categories, featuring coarse and fine threads (class 2A) along-with clear zinc finish. Usually ASTM A-354 and SAE J-429 Grade 5 bolts are available in the market. These are available in 1/4″ to 1-1/2″ diameters and 14″ of length.

If ever you like to compare this grade with any other grade say Grade 8 and Google on this comparison, you would be bombarded with a long thread. You would be amazed to find some forums and discussion rooms, where people have referred grade 5 as superior to grade 8, which is absolutely illogical.

You can easily come across various old wives’ tales even at some renowned publishing sites. Such myths act as a catalyst to enumerate such kind of wrong information.

Here’s a snippet from Sept’ 2011 issue: 

In actual fact, Grade 5 bolts are often preferred over Grade 8 . A Grade 8 bolt has a very high tensile strength, but can be brittle. In applications such as suspensions, a very high number of load/unload cycles can produce work hardening, which produces an immediate, or catastrophic failure. It’s often much safer to use a Grade 5 bolt which will bend, thus providing a warning, rather than a Grade 8 bolt breaking without warning. As long as the Grade 5 bolt has been sized large enough to take the expected load, we don’t want to trade toughness (resistance to stress cycles) for the ultimate tensile strength of the Grade 8 fastener.

It’s true that grade 5 is an ideal fastener suitable for various applications, but to state that a grade 5 bolt is preferred over grade 8 bolt for mounting suspension components can be quite dangerous, as a beginner can believe such information and can try for such applications.

In this snippet, while the writer has left behind an admonition stating that grade 5 bolt will warn us before breaking, such statement has raised a great debate urging the experts to clear such myth prevailing with grade 5 bolts.

If we logically think over this comparison, we will realize that it doesn’t make any sense how a “softer and malleable bolt” can be superior than a brittle grade 8 bolt. In a layman’s point of view, one can understand that when the grade level increases, the features and durability also increases.

And if we think in the line of toughness then how come a bolt of lower grade can be tougher than a bolt of higher grade? Below is a chart stating the specifications of these bolts. Please have a look to understand the difference.

If we go through the mechanical properties, it’s clearly evident that in all aspects, Grade 8 bolts are superior than Grade 5 bolts.

To have a deep knowledge on this, you can visit websites like SAE and BoltScience, where you can get tested information. Even fastener suppliers like Mutual Screw and Supply render specification charts with their every displayed products.

However, there has always been an undying debate going on this when it comes to choosing either grade 5 or grade 8. While some people go by book knowledge, others prefer to learn from their experience.

In one of forums, somebody defines brittle as very strong, which does not allow strain before failure, and defines ductile as not so strong, but enables significant elastic deformation.

Grade 8 bolts fail because of strength, whilst grade 5 bolts fail because of toughness.