Asked by: Eyal Albarral
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What is the difference between a325 and Grade 8 bolts?

Last Updated: 30th May, 2021

A325 bolts are typically manufactured from a medium carbon steel (although they can be made from an alloy) while SAE grade 8 bolts are made from a medium carbon alloy steel. Grade 8 bolts are significantly stronger than an A325. An ASTM specification with similar strength properties to grade 8 is ASTM A490.

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Regarding this, what grade is an a325 bolt?

ASTM A325 is the standard specification for heavy hex structural bolts in heat-treated steel with a minimum tensile strength of 120/105 ksi. A325 bolts from Glaser and Associates are available in two grades, type 1 and type 3, offering different mechanical and chemical properties for specific applications.

Similarly, how can you tell if a bolt is grade 8? Look for Bolt Markings If you do not have a magnet you can still identify Grade 8 bolts by brushing the head of the bolt using a wire brush and counting its radial lines. There are six radial lines on the heads of Grade 8 bolts. Length is measured from under the head.

Also to know, are all Grade 8 bolts the same?

Different grades of bolts are composed of different metal alloys and therefore have different mechanical properties. Grade 8 bolts are made of quenched and tempered medium carbon alloy steel. They are about twice as strong as grade 2 bolts, which are made from untempered carbon steel.

What is a Grade 8 bolt made of?

From the internet: Grade 8 bolts are comprised of carbon alloy steel, thus giving them a high psi rating. Zinc or yellow zinc grade 8 bolts are available to resist corrosion. The factor that makes a grade 8 bolt different from a lower grade bolt is its preload strength.

Related Question Answers

Nounout Aquebeso


Are a325 bolts high strength?

A325 bolts have a minimum tensile strength of 120,000 PSI for one inch or less diameters and 105,000 PSI for over one inch. This makes them weaker than A490, certain jobs do not require a structural bolt as strong as Grade A490.

Deisy Egues


Are a307 bolts high strength?

ASTM A307 bolts are not assigned to a group since they are not considered to be high strength bolts. The ultimate tensile strengths for A325 and A490 bolts are 120 ksi and 150 ksi respectively.

Lloyd Asteyssa


What does a325 bolt mean?

ASTM A325 is an ASTM International standard for heavy hex structural bolts, titled Standard Specification for Structural Bolts, Steel, Heat Treated, 120/105 ksi Minimum Tensile Strength. It defines mechanical properties for bolts that range from 12 to 1 12 inches (13 to 38 mm) in diameter.

Olatz Zepponi


Can a325 bolts be reused?

Reuse: ASTM A490 bolts and galvanized ASTM A325 bolts shall not be reused. When approved by the Engineer of Record, plain finish ASTM A325 bolts are permitted to be reused. Touching up or re-tightening bolts that may have been loosened by the installation of adjacent bolts shall not be considered to be a reuse.”

Tareq Elbeze


What is the strongest bolt material?

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.

Jurijs Garcia Gil


What is the tensile strength of a325 bolts?

Grade A325 bolts are available in diameters from 1/2 to 1-1/2 inch (for diameters greater than 1-1/2, ASTM A449 specifications should be considered) with a minimum tensile strength of 120,000 PSI. They also come in two types.

Timur Gribashev


Are Grade 5 bolts stronger than Grade 8?

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.

Teslem Hustedt


Can Grade 8 bolts be galvanized?

By reviewing Table 1 below, it is clear that specifications ASTM A490, ASTM A354 grade BD, and SAE J429 grade 8 are all potentially susceptible to hydrogen embrittlement and should therefore not be hot-dip galvanized.

Dragomir Fuchtjohann


Is a 10.9 Bolt stronger than Grade 8?

Zinc plated for moderate corrosion resistance. A tempered medium carbon steel. Class 10.9 is stronger than class 8.8, and is commonly found in high strength automotive applications. Class 10.9 is similar to grade 8.

Oumarou Hefter


What is the tensile strength of a Grade 8 bolt?

Grade 8 bolts are designated as a 150 ksi. This means its tensile strength or the resistance it has before it is subject to breaking under tension is equal to 150,000 lbs. per square inch. In comparison, a Grade 5 bolt is weaker as its tensile is 120 ksi, placing it at 120,000 lbs.

Ivailo Lipman


Is stainless steel bolts stronger than Grade 8?

Stainless steel bolts are rated for corrosion resistance. Bolt strength is rated in PSI (pounds per square inch). A stainless steel bolt has the same PSI rating as a grade 5 bolt (125,000 PSI). A grade 8 bolt has a stronger rating with a PSI of 150,000.

Sorina Teufel


Can you thread a Grade 8 bolt?

If the hardness of the part to be threaded is close to, or equal to the hardness of the threading tool, cutting will not occur. Grade 8 cannot be readily threaded; too hard. Why do the threads need to be extended in the first place, can't the correct size bolt be found 'off the shelf'?

Asad Nieman


What color is a Grade 8 bolt?

Grade 8 bolts are made of a medium carbon alloy steel that is also quenched and tempered and are the most durable bolts you can purchase for automotive use. They can be identified by the five radial lines on the head of the bolt and are usually (but not necessarily) gold in color.

Sania Maasz


What does 8.8 on bolt head mean?

If you have ever looked a metric hex bolt you might notice the markings 8.8, 10.9 or 12.9 this does not mean grade 8,10 or 12. The grade 8.8 refers to the tensile strength which is generally 116,000 psi, grade 10.9 is generally 150,000 and grade 12.9 is generally 175,000 psi.

Eliecer Shields


What do the markings on bolts mean?

What do they mean? The lines on the head of a bolt indicate its grade. SAE J429 (Society of Automotive Engineers) bolts have radial lines, whereas ASTM (American Society for Testing and Materials) uses a combination of letters and numbers to indicate the grade.

Hyun Caiz


How strong is a grade 12.9 bolt?

The minimum tensile strength of a 12.9 bolt is 1220 MPa. Therefore, the approximate shear strength of a 12.9 bolt is 732 MPa. The minimum yield strength of a bolt is the pressures needed to stretch the metal of the bolt. A 12.9 bolt has a minimum yield strength of 1100 MPa.

Adelino Hoffma


What grade bolt do I have?

Video 1: Determining Bolt Grade and Head Markings
Grade Material Proof Load psi
Grade 5 3 Radial Lines Medium Carbon Steel 74,000
Grade 8 6 Radial Lines Medium Carbon Alloy Steel 120,000
Metric 8.8 Medium Carbon Steel 580

Zinoviya Usigno


What is the hardest bolt?

The world's strongest bolts are stainless
  • BUMAX® Ultra – the world's strongest bolt.
  • Nobel Prize winning technology.
  • Demanding applications.
  • Replacing carbon steel fasteners in critical applications.