The symbols on top of bolts generally indicate what type of bolt it is. The type of bolt commonly found on machines and vehicles are hex head (or hex cap) bolts and the symbol for these is a hexagon shape.
Other common symbols used for bolts include a flat or oval head, which is indicated by a flat top, or a button head, which is indicated by a rounded top. All of these symbols provide a quick visual way of identifying the types of bolts.
In addition to these symbols, it is also common to find numbers on the bolts as well. This number indicates the size of the bolt and is generally either metric or Imperial. Metric bolts are typically 2 characters, followed by the letter “M” and the size typically ranges from 3mm to 24mm or larger.
Imperial bolts may be either 2 or 3 characters, followed by a number and the letter “S” indicating the size, typically ranging from 1/4 inch to 3/4 inch or larger.
In some cases, you may also find symbols that indicate the thread type, grade, or material on bolts. These symbols are not as common as the symbols used for identifying bolt types and sizes, but can provide additional information about the bolt itself.
In summary, the symbols on top of bolts commonly indicate what type of bolt it is, the size of the bolt, and may also indicate the grade, thread type, or material the bolt is made from. Knowing the symbols for the different types of bolts and the sizes can help when identifying or identifying the right bolts for a particular job.
What does it mean to stripe a bolt?
Stripping a bolt means to tighten the head of the bolt so that the threads of the bolt cannot be fully engaged in the nut; ultimately, it can no longer hold the two parts together correctly. This commonly happens when someone tightens the bolt with a wrench, pliers, or a ratchet that is too small and slips when high torque is applied, resulting in the bolt head being forced off of the thread, damaging the thread of the bolt.
The bolt is said to be stripped when it is incapable of properly threading with a nut. Stripped bolts can be extremely difficult to remove, and usually require the use of a power drill or a hacksaw to cut away the damaged threads before the bolt can be taken out.
What grade is a bolt with 2 lines?
A bolt with 2 lines is typically grade 5. Grade 5 is the most common grade for bolts and is made from medium-strengthSteel. It is stronger than grade 2 bolts, but it is not as strong as grade 8 bolts, which are commonly found in high-load applications like engine components, axles, and engine mounts.
Grade 5 bolts can be used in a variety of applications, including those that require medium strength, such as vehicle frames and engine blocks. Grade 5 bolts are usually zinc plated, making them rust-resistant and able to handle medium-duty applications.
What grade bolt is stronger 5 or 8?
Grade 8 bolts are generally considered to be the strongest, with a higher tensile strength than Grade 5 bolts. Grade 8 bolts meet a minimum hardness of 150,000 PSI, and grade 5 bolts have a minimum of 120,000 PSI.
Both grades offer corrosion resistance and are generally considered to be strong and durable. However, Grade 8 bolts have a higher force and shear strength, making them the stronger option of the two grades.
Grade 5 bolts are suitable for many applications, but for particularly heavy duty jobs or anything that needs to withstand extreme force or conditions, Grade 8 bolts are generally recommended.
What is the strongest bolt grade?
The strongest bolt grade is typically grade 8. Grade 8 bolts are made from alloy steel and are hardened to resist shearing and breaking. They generally have a high tensile strength, meaning they’re good for holding together heavy loads.
Grade 8 bolts have a tensile strength of at least 150,000 psi and are marked with six radial lines in a clockwise pattern. The strength of the bolt increases as the number of radial lines increase, with six radial lines indicating the highest level of strength.
Grade 8 bolts are typically used for high-load applications, such as engine and transmission parts, automotive components, securing heavy machinery, and most other heavy-duty applications.
What bolt head has 6 lines?
The 6-Lobe or 6-Lobule bolt head is a type of fastener head with six rounded protrusions (“lobes”). These lobes form a hexagonal pattern on the head when viewed from above. This design helps to make the bolt head more secure in its fastened position, preventing it from being easily turned or loosened with a standard wrench or screwdriver.
The 6-Lobe bolt head is especially useful in applications where extra strength and security is needed, such as automotive and military applications. It is also often used in consumer products, such as laptops, phones, gaming systems and more.
The 6-Lobe bolt head is available in a variety of sizes and materials, depending on the desired application.
How do you read a bolt drawing?
Reading a bolt drawing is fairly straightforward. First, make sure you have a copy of the drawing and familiarize yourself with the abbreviations used in the diagram. Bolt drawings usually include the bolt diameter, thread pitch, shank length, head shape, and a keyed washer.
It’s important to know what each of these symbols mean. After you’ve identified them, you can then measure the size of the bolt to ensure that it’s the correct size. If it’s not, you may need to find a replacement that matches the size of the original.
Next, you’ll need to check the thread pitch. This is typically measured in threads per inch (TPI) and is indicated by arrows pointing towards each thread. You’ll need to measure this accurately to make sure the nut or other fastener you’re using will fit the threading on the bolt.
After measuring the diameter and thread pitch, you’ll need to look at the shank length. This is simply the length of the bolt from the head to the end of the threads. It’s important to make sure the shank length is long enough to allow you to use it in the application.
Finally, you’ll need to look at the head shape. This should either be specified in the drawing or you can measure it to make sure it matches the nut or other fastener that you’re using.
Once you’ve done all these measurements and verified that they’re correct, you can then proceed to assemble and fasten your project.
How do you identify bolt grade markings?
Identifying bolt grade markings can be done by familiarizing yourself with the American Society for Testing and Materials (ASTM) aluminum, steel, and stainless steel grades. ASTM uses a standard bolt grade marking system to identify the strength of the different bolts.
The markings are generally made of raised or depressed lines and/or numbers that can be found on the head of each bolt. Most commonly, you will find the following markings on bolts:
Grade 2 bolts are marked with a number 2 followed by a hexagonal symbol (a six-sided figure). Grade 5 bolts feature three radial lines. Grade 8 bolts have six radial lines.
ASTM A325 bolts are marked with the “A325” imprint and have three radial lines. ASTM A490 bolts have in a similar way, have four radial lines and the marking “A490” imprinted on the bolt’s head.
In a few cases, bolt markings may include additional numbers next to the grade symbol. Those extra numbers are creation dates that are meant for internal use only and are not connected to the grade of the bolt.
Finally, it is important to note that bolt grade markings can vary from one type of bolt to another. It is important to study the specific standard the bolt is manufactured to. If the maker of the bolt is unknown, you can refer to the ASTM standards to identify the grade and strength of the bolt.
What is the difference between 8.8 and 10.9 bolts?
The difference between 8. 8 and 10. 9 bolts is their grade and strength. 8. 8 grade bolts are made of medium carbon steel and are quenched and tempered. They have a minimum tensile strength of 800MPa and a minimum yield strength of 640MPa, making them suitable for general use in applications such as farm machinery, trailers and some construction applications.
10. 9 grade bolts are made of higher grade alloy steel and have a minimum tensile strength of 1040MPa and a minimum yield strength of 940MPa, making them the preferred choice for applications where greater strength is required such as those in the automotive and aerospace industries.
8. 8 bolts are also less expensive than 10. 9 bolts.
What do bolt grades mean?
Bolt grades, sometimes referred to as strength grades, signify the level of strength and durability of a bolt. Bolt grades are typically represented by a numerical value, with higher numbers indicating higher-quality materials and greater strength.
Generally, bolt grades range from 1 up to 12 and beyond, with grade 12 bolts providing the highest levels of strength and durability. Grades 1-3 are usually considered soft bolts, while grades 8-12 are typically regarded as hardened, high-strength bolts.
Bolts are designed to withstand different loads, as specified by their grade. In most cases, the grade of a bolt indicates its tensile strength, also known as its yield strength. This is the amount of force required to cause the bolt to yield, deform, or permanently stretch.
Tensile strength increases with bolt grade, with Grade 12 bolts having the highest tensile strength rating (120,000 PSI).
It’s important to select the appropriate grade of bolt for the job, as incorrectly delegating a lower-grade bolt for a higher-duty purpose can result in fracture or even complete failure of the bolt.
While Grade 5 bolts are commonly used for most general purpose applications, Grade 8 or higher are often reserved for heavy-duty applications. For structural purposes, a structural bolt meeting the requirements of ASTM A325 or A490 is typically recommended.
How do I identify a bolt?
Identifying a bolt can be done by examining the head, threading, and size.
The head of the bolt can be either an external hex head, square head, or round head to name a few. It can also have a variety of special features such as a built-in washer, surface-hardening, or corrosion protection.
If the head of the bolt has numbers imprinted on it, this can also be a very helpful hint for identification.
Next, the threading of the bolt can be used to help identify it. On most bolts, the threading will appear on either the shank (the body of the bolt) or the head. The threading can be either inch or metric, coarse or fine, and left or right hand.
It is important to note that the threading is not always external and can sometimes be internal. It is also important to note the pitch, diameter, shape of the threading, and presence of grooves.
Lastly, size is also a major factor to consider when identifying a bolt. The size of the bolt is expressed in either millimeters or inches, depending on the type of threading. The length and diameter of the bolt will also affect the size, with lengths typically expressed in fractions of an inch or multiples of a millimeter.
Combining all of these factors can help you identify the type of bolt you are working with. It is often easiest to take measurements of the bolt and use a bolt identification chart to accurately identify the bolt.
Alternatively, you can bring the bolt in to a hardware store to be identified by their experienced staff.
How can I tell what kind of bolt I have?
First, look at the markings on the bolt itself; different bolts often have different markings that allow you to identify them. Additionally, consider the shape of the head – bolts come in different head types such as hex, flat, or button – as well as the way it threads (coarse, fine, or reverse).
Lastly, you can use a caliper to measure the bolt size. Inch-based bolts are measured according to the diameter of their shank, while the metric system is measured according to the distance between threads.
Understanding these basics helps to narrow down the type of bolt you have.
Is there an app to identify nuts and bolts?
Yes, there are apps available that can help identify nuts and bolts. The iFixit Maintenance Companion app for Android and Apple can help you identify and size nuts and bolts. Additionally, the Bolt Identification app allows you to easily determine the type and size of nuts and bolts.
It can also provide detailed images, helpful descriptions, and comparative images, so you can be sure of the correct type and size of the fastener you need. The Hardware Solution App can also help with the identification and sizing of nuts and bolts.
You can also find apps that specialize in a specific type of fastener such as Nuts and Bolts Finder, which specializes in machine screws and bolt types.
How are bolts marked?
Bolts are marked with a unique number and/or lettering to indicate their specifications, such as the size, material, and other features. The markings may appear on the head of the bolt or on the shank.
For standard sized bolts, the markings indicate the manufacturer, length, diameter, thread pitch, and grade. In particular, common sizes such as 1/4-20 UNC, 3/8-16 UNC, and 5/16-18 UNC have generally identifiable markings.
For example, a 5/16-18 UNC bolt may be marked “5/16-18 UNC (2A)”. This indicates that the bolt is made to the specifications of the American Society for Testing and Materials (ASTM) grade 2A.
Metric-sized bolts are typically marked with metric dimensions. For example, an 8 mm x 1. 25 mm bolt may be marked “M8-1. 25 X 25”. In some cases, the metric bolt markings may also indicate the grade of the bolt.
For example, an 8. 8 grade bolt may be marked as “M8-1. 25 X 25 (8. 8)”.
When measuring a bolt, it is important to use the proper measuring tools and to look at the markings carefully, in order to ensure the accuracy of the measurements. As such, bolts should be marked clearly and legibly to avoid confusion and ensure the right bolt is used for the application.
How are bolts specified and identified?
Bolts are typically specified according to the standards set by the American Society of Mechanical Engineers (ASME). Generally speaking, bolts will be identified by their size, thread diameter, length, material, and coating.
To further specify a bolt, you would mention its type and grade as well. For example, a common grade 2 bolt is an ASTM A307 bolt with a coarse thread.
The size and thread diameter of a bolt refer to its outer diameter and thread count, respectively. The length of a bolt typically refers to its overall length, from the head to the tip, and is measure in more precise fractions and inches.
The material of a bolt denotes the grade, composition, and strength of the bolt and is commonly represented by codes such as SAE and ASTM. To determine the exact material, you may need to consult a catalog or your manufacturer.
Lastly, the coating of a bolt is an optional feature that helps protect it against rust, corrosion, and other environmental factors. Some common coatings are cadmium, zinc, and black oxide.
