- Systems of Bolt Grades. Bolts are made of different grades of steel. The grade of a bolt determines the maximum amount of stress (tensile strength) that the bolt can handle.
- Bolt Grade Markings. The most common grading system used for bolts in the U.S. is the SAE system, but you can find metric grading systems as well.
- SAE Bolt Grades. This bolt is an ASTM specification bolt that’s readily available in many home improvement and automotive stores.
- Metric Bolt Grades. Head Marking: 8.8 Head Marking: 10.9 Head Marking: 12.9 No matter the types of bolts you need for your home or mechanical project, The Home Depot has ...
How can you identify a Grade 5 bolt?
- Systems of Bolt Grades. Bolts are made of different grades of steel. ...
- Bolt Grade Markings. The most common grading system used for bolts in the U.S. ...
- SAE Bolt Grades. This bolt is an ASTM specification bolt that’s readily available in many home improvement and automotive stores.
- Metric Bolt Grades. ...
Which is stronger grade 8 or grade 5 bolts?
There exists an often quoted myth, that Grade 5 bolts are better in shear than Grade 8 since they will bend before breaking. Not true. Shear strength of alloy steel is approximately 60% of its ultimate tensile strength. Reference to Table 1 shows that the yield strength of a Grade 8 bolt is higher than the ultimate strength of a Grade 5 bolt.
How is the grade strength of a bolt determined?
There are three primary materials used in the making of A325 bolts, and they are:
- Type 1 – medium carbon steel or alloy steel, or boron steel
- Type 2 – low carbon martensitic steel (this designation was removed from the standard in 1991)
- Type 3 – weathering steel
What is the strongest bolt grade?
Thereof, what grade Bolt is the strongest? The strongest commercial-quality bolt is grade 8, marked by six raised dashes; its medium-carbon alloy steel has been quenched and tempered to achieve a tensile strength of 150,000 psi. Subsequently, question is, what is shear strength of bolts?
How can you tell if a bolt is a Grade 5?
Grade 5. Manufactured from medium carbon steel and hardened for greater strength and durability, a grade 5 bolt is distinguished by 3 radial lines and promises tensile strengths between 105,000 and 120,000 psi. They are most commonly found in automotive applications or those that require medium strength.
What does 9.8 mean on a bolt?
Higher Number Means Stronger The higher the ISO numbers are, the stronger the bolt. A metric bolt designated as ISO class 6.8 roughly corresponds in strength to an SAE Grade 2 bolt. Bolts of ISO class 8.8 and the slightly stronger class 9.8 roughly correspond to an SAE Grade 5 bolt.
What does a 7 on a bolt mean?
The marks approximately correspond to the following property classes: Head Mark "4": 4.6, 4.8, 5.6, 5.8, 6.8. Head Mark "7": 8.8. Head Mark "8": 9.8.
What does 4.8 mean on a bolt?
Metric steel bolts, screws and studs - proof and tensile strength.Property ClassSize Range (mm)Minimum Proof Strength (106 Pa)4.6M5 - M362254.8M1.6 - M163105.8M5 - M243808.8M1.6 - M366003 more rows
Is Grade 8 or 10.9 stronger?
Class 10.9 is stronger than class 8.8. It is commonly found in high strength automotive applications. Class 10.9 is similar to grade 8.
Is Grade 8 or 12.9 stronger?
Used in high stress environments, grade 12.9 fasteners are the highest class of metric cap screws. Where Grade 8 fasteners have a 150,000 psi tensile strength, 12.9 fasteners have a 180,000 psi tensile strength, making them more durable than the grade 5.
How do you read a bolt?
0:212:23How to Measure Screws & Bolts - US & Metric Sizing | Fasteners 101YouTubeStart of suggested clipEnd of suggested clipSo when you read a bolt that says quarter 20 by 2 that means quarter inch diameter 20 TPI that'sMoreSo when you read a bolt that says quarter 20 by 2 that means quarter inch diameter 20 TPI that's threads per inch which would be here.
What does 4.6 mean on a bolt?
In 4.6, The first number 4 indicates 1/100 of nominal tensile strength . Hence the tensile strength = 400 Mpa. The second number indicates 10 times the ratio between lower stress(proof stress) and nominal tensile strength(yield stress ratio) means, 10 times the yield stress = 10 x 240/400 = 2400/400 = 6.
What does 3 lines on a bolt mean?
The markings can identify the standard to which the bolt was made. For instance, if a bolt head contains three radial lines, then it's a Grade 5 bolt. If it contains five radial lines, then the bolt is Grade 8.
What does 8.8 mean on bolt?
So, in English, a Property Class 8.8 bolt is a bolt with a nominal tensile strength of 800 MPa and a nominal yield strength that is 80% of that nominal tensile strength, so 640 MPa.
What grade is an 8.8 bolt?
Grades of Bolts - Bolt Grade Markings & Bolt Strength ChartBolt Grade Markings & Strength Chart - Metric Steel BoltsGrade/SpecificationTensile Strength min (MPa)Class 4.6400 (58,000 psi)Class 5.8520 (75,000 psi)Class 8.8830 (120,000 psi)4 more rows
What is the difference between Grade 5 and Grade 8 bolts?
Grade 8 bolts have been hardened more than grade 5 bolts. Thus they are stronger and are used in demanding applications such as automotive suspensions. Grade 8 bolts have 6 evenly spaced radial lines on the head. Grade G is roughly equivalent to Grade 8.
What does grade mean on a bolt?
This is a technical term which determines the properties of a bolt. The grade of a bolt determines the maximum amount of stress that the bolt can handle.
What are the different grades of bolts?
Let us have a look at each grade and its properties: Grade 2 – The grade 2 bolts are most commonly manufactured from low or medium carbon steel.
What are bolts used for?
Bolts. What are they? These are the components which are also referred to as fasteners and are used to hold two objects firmly together. There are certain things that are very crucial to consider while selecting the right bolt for an application.
How to tell the strength of a bolt?
You can usually figure out the grade, or strength, of a bolt by looking at the markings on its head. English bolts (U.S.S. or S.A.E) are categorized by grade, from grade 2 to grade 8, where the grade represents inch strength. The higher the grade, the stronger the bolt. English bolts have radial lines on their head to identify the grade, ...
How many radial lines are there on a grade 8 bolt?
A grade 8 bolt will have 6 radial lines on its head. Metric bolts are a bit more straight forward, usually having their strength class number stamped right on the bolt head. Some metric nuts also have the strength class number stamped on their face. The below diagram shows examples of English and Metric bolt and nut markings.
Why do English bolts have radial lines?
The higher the grade, the stronger the bolt. English bolts have radial lines on their head to identify the grade, or strength class. The number of lines on the bolt head is 2 less than the actual grade. So, for example, a grade 5 bolt will only have 3 radial lines on its head.
How to tell if a bolt is metric or standard?
Most bolts come in pretty uniform lengths; and this is a good way to determine if the bolt is metric or standard. Measure the bolt length (not including the cap), and see if it’s closer to a fraction of an inch, or a nice and round millimeter length that ends in 5 or 0. Sometimes bolts can be a very specific length and this way might not always ...
What is a low grade bolt?
Low grade bolts are going to work for most everyday applications, like mounting a flat screen television, or keeping your chair together. The higher grade bolts are reserved for heavier machinery that really need that extra strength.
What is a bolt made of?
The bolts we deal with are primarily made from steel, which is an iron alloy that rusts . Most bolts are coated with zinc (galvanization), which makes it corrosion resistant.
Does stainless steel rust?
Against popular belief stainless steel does rust, but at a very slow rate. Stainless steel is just steel with varying amounts of chromium, the more chromium the more protected it is from the elements, like water. When it comes to water, you have stainless steel for fresh water (type 304) and stainless steel for salt water (type 316). Zinc plated steel is good for open air, stainless steel is good for fresh water, and “marine grade” stainless steel is good for salt water.
Is a coarse metric bolt fine?
As you can see, the thread pitch of the coarse metric bolt is much finer than a coarse thread standard bolt. It’s hard to tell, but the fine thread standard bolt is just slightly finer then a regular coarse thread metric bolt. For bonus points here, you will notice these bolts aren’t made from the same materials.
