The two different types of bolts are a325 and Grade 8. The large size difference is how they were designed for the job, with an increase in strength from grade 8 to a 325 bolt. Both have similar benefits but it all depends on what you want your project or building to do specifically before choosing which type of bolt to use.
“Grade 8 bolts” are a type of bolt that is typically used in construction. They are stronger than the grade 9 bolts, but they are not as strong as the a325 bolts. Grade 9 bolts can be used for all-purpose applications. The grade 8 bolts have a higher tensile strength and yield strength than grade 9 bolts.
SAE grade 8 bolts are composed of a Alloy Steel with a Medium Carbon Content, while A325 bolts are normally constructed of a Steel with a Medium Carbon Content (although they may be produced from an alloy). A325 bolts are substantially weaker than Grade 8 bolts. ASTM A490 is an ASTM standard with equivalent tensile qualities as grade 8.
What grade is an a325 bolt, anyway?
The ASTM A325 standard specifies heat-treated steel heavy hex structural bolts with a minimum tensile strength of 120/105 ksi. Glaser & Associates’ A325 bolts come in two grades: type 1 and type 3, each with its own set of mechanical and chemical qualities for specialized purposes.
Similarly, how do you know whether a bolt is grade 8? Keep an eye out for Bolt Markings. If you don’t have a magnet, you may still identify Grade 8 bolts by using a wire brush to brush the head of the bolt and counting the radial lines. The heads of Grade 8 bolts have six radial lines. The length is measured from the base of the neck to the top of the head.
Are all Grade 8 bolts the same in this regard?
Bolts of various classes are made up of different metal alloys and so have varying mechanical qualities. Grade 8 bolts are constructed of Alloy Steel with a Medium Carbon Content that has been quenched and tempered. Grade 2 bolts, which are constructed of untempered carbon steel, are nearly twice as strong.
What is the composition of a Grade 8 bolt?
According to the internet: Because Grade 8 bolts are made of carbon alloy steel, they have a high psi rating. To withstand corrosion, zinc or yellow zinc grade 8 bolts are offered. The preload strength of a grade 8 bolt differentiates it from a lesser grade bolt.
Answers to Related Questions
Are a325 bolts considered to be high-strength?
Bolts with a diameter of one inch or less have a minimum tensile strength of 120,000 PSI, while bolts with a diameter of more than one inch have a minimum tensile strength of 105,000 PSI. Because they are weaker than A490, some projects do not need the use of a structural bolt of Grade A490.
Are a307 bolts considered to be high-strength?
Because ASTM A307 bolts are not considered high-strength bolts, they are not allocated to a category. A325 and A490 bolts have ultimate tensile strengths of 120 and 150 ksi, respectively.
What does the term “a325 bolt” mean?
Standard Specification for Structural Bolts, Steel, Heat Treated, 120/105 ksi Minimum Tensile Strength is an ASTM International standard for heavy hex structural bolts. It specifies the mechanical characteristics of bolts with diameters ranging from 12 to 12 inches (13 to 38 mm).
Is it possible to reuse a325 bolts?
“Reuse: Galvanized ASTM A325 bolts and ASTM A490 bolts must not be reused. Plain finish ASTM A325 bolts may be reused with the approval of the Engineer of Record. Touching up or re-tightening bolts that may have been loosened as a result of the installation of neighboring bolts is not considered a reuse.”
What is the tensile strength of a bolt?
Grade 8, denoted by six elevated dashes, is the strongest commercial-quality bolt; its medium-carbon alloy steel has been quenched and tempered to attain a tensile strength of 150,000 psi.
How strong are a325 bolts in terms of tensile strength?
Bolts of Grade A325 have a minimum tensile strength of 120,000 PSI and come in sizes ranging from 1/2 to 1-1/2 inch (for diameters higher than 1-1/2, ASTM A449 requirements should be consulted). They are also available in two varieties.
Are Grade 5 bolts more durable than Grade 8 bolts?
Bolts in grades 8 and 8 have been hardened more than bolts in grades 5 and 5. As a result, they are more durable and are employed in high-demand applications like car suspensions. On the head of Grade 8 bolts, there are six equally spaced radial lines. Grade G is almost the same as Grade 8.
Is it possible to galvanize Grade 8 bolts?
Table 1 shows that the ASTM A490, ASTM A354 grade BD, and SAE J429 grade 8 requirements are all vulnerable to hydrogen embrittlement and should not be hot-dip galvanized.
Is a 10.9 Bolt more powerful than a Grade 8 Bolt?
Corrosion resistance is modest because to the zinc plating. A Steel with a Medium Carbon Content that has been tempered. Class 10.9 is a higher-strength version of class 8.8 that is often used in high-strength automotive applications. Class 10.9 resembles grade 8.
What is a Grade 8 bolt’s tensile strength?
Grade 8 bolts have a 150 ksi rating. This indicates that its tensile strength, or the resistance it possesses before breaking under stress, is 150,000 pounds per square inch. A Grade 5 bolt, on the other hand, is weaker, with a tensile strength of 120 ksi and a weight of 120,000 lbs.
Are stainless steel bolts more durable than Grade 8 bolts?
Corrosion resistance is a feature of stainless steel fasteners. Bolt strength is measured in pounds per square inch (PSI) (pounds per square inch). The PSI rating of a stainless steel bolt is the same as that of a grade 5 bolt (125,000 PSI). With a PSI of 150,000, a grade 8 bolt has a higher rating.
Is it possible to thread a Grade 8 bolt?
Cutting will not occur if the hardness of the component to be threaded is near to, or equal to, the hardness of the threading tool. It is impossible to thread Grade 8 since it is extremely difficult. Why do the threads need to be expanded in the first place when a suitable bolt can be obtained ‘off the shelf’?
A Grade 8 bolt is what color?
Grade 8 bolts are the most durable bolts available for automotive application, since they are constructed of a Alloy Steel with a Medium Carbon Content that has been quenched and tempered. The five radial lines on the head of the bolt identify them, and they are generally (but not always) gold in color.
What does the number 8.8 on the bolt head mean?
If you’ve ever glanced at a metric hex bolt, you’ve probably noticed that the numbers 8.8, 10.9, or 12.9 don’t signify grade 8, 10, or 12. The tensile strength of grade 8.8 is about 116,000 psi, grade 10.9 is around 150,000 psi, and grade 12.9 is approximately 175,000 psi.
What do the bolt marks mean?
What exactly do they imply? The grade of a bolt is indicated by the lines on its head. Bolts with radial lines are SAE J429 (Society of Automotive Engineers), while ASTM (American Society for Testing and Materials) uses a mix of letters and numbers to identify the grade.
What is the strength of a grade 12.9 bolt?
A 12.9 bolt has a minimum tensile strength of 1220 MPa. As a result, a 12.9 bolt’s estimated shear strength is 732 MPa. The forces required to strain the metal of a bolt are known as its minimum yield strength. The minimum yield strength of a 12.9 bolt is 1100 MPa.
What is the grade of the bolt I have?
Determining Bolt Grade and Head Markings (Video 1)
|Grade||Material||psi Proof Load|
|3 Radial Lines, Grade 5||Steel with a Medium Carbon Content||74,000|
|6 Radial Lines, Grade 8||Alloy Steel with a Medium Carbon Content||120,000|
|8.8 metric||Steel with a Medium Carbon Content||580|