- What is the difference between a 10.9 and 12.9 Bolt?
- What is the difference between 8.8 and 12.9 grade bolts?
- What grade is a 12.9 bolt?
- Are Grade 8 bolts brittle?
- What does 12.9 mean on a bolt?
- Is a 12.9 Bolt stronger than Grade 8?
- How many grades of bolts are there?
- What is the hardest bolt you can buy?
- Is Grade 8 or 10.9 stronger?
- How hard is a 10.9 bolt?
- What is the highest grade bolt?

## What is the difference between a 10.9 and 12.9 Bolt?

For most applications, property class 10.9 fasteners gives the best compromise between strength and brittle fracture risk.

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(For example the fatigue endurance strength of a typical 12.9 fastener is the same as that for a 10.9 or an 8.8 fastener.).

## What is the difference between 8.8 and 12.9 grade bolts?

The mechanical difference between the 12.9 and 8.8 is yield strength (roughly 90% of 1200 MPa vs 80% of 800 MPa). That means the 12.9 can be stretched further (i.e. torqued to some higher value) before it yields, which of course increases the clamp force.

## What grade is a 12.9 bolt?

The 12.9 is the Class head marking under ASTM F568M standard for Bolts of a high grade (1220 MPa), being Alloy steel, quenched and tempered.

## Are Grade 8 bolts brittle?

A Grade 8 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.

## What does 12.9 mean on a bolt?

The 12.9 is the Class head marking under ASTM F568M standard for Bolts of a high grade (1220 MPa), being Alloy steel, quenched and tempered.

## Is a 12.9 Bolt stronger than Grade 8?

A quick internet search shows that Class 8.8 has a yield strength of 660 MPa while Class 12.9’s yield strength is 1100 MPa.

## How many grades of bolts are there?

There are several grades of bolts but the three common grades for SAE are 2, 5 and 8. The common class (grades) for metric are 5.8, 8.8, 10.9 and 12.9. Each grade has a specific bolt strength. No matter the system used to grade the bolts, the higher the number means the stronger the bolt.

## What is the hardest bolt you can buy?

BUMAX® Ultra – the world’s strongest bolt Since its launch in 2014, the BUMAX® Ultra range has proven that it is capable of exceeding tensile strengths of between 1 500 to 1 700 MPa on various applications, with good corrosion resistance and an operating range of between -50 and 400°C.

## 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. A low carbon steel for general use.

## How hard is a 10.9 bolt?

Used in automotive applications and for bolting large and forged parts, metric 10.9 bolts exhibit high tensile strength and good wear resistance. Our metric grade 10.9 bolts meet ASTM A324 grade BD and SAE J429, grade 8 standards. The yield strength of the bolts is 940 and the tensile strength is 1040 MPa.

## What is the highest grade bolt?

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.