What does the 10.9 on a bolt mean?

Property Class 10.9 bolts and screws have a minimum tensile strength of 1040 MPa for all sizes. As you can see, they're slightly stronger than the nominal value in the property class designation. Property Class 10.9 bolts are considered high-strength parts. They're in the neighborhood of SAE J429 Grade 8 parts.

Which is stronger 12.9 or 10.9 steel?

The tensile strength of 12.9 grade steel is 120 percent more than that of 10.9 grade steel.

What does 12.9 mean on a bolt?

In metric classes, bolts that have been graded as 12.9 have the highest strength. In comparison to grade 8.8, the strength of Grade 12.9 Bolts is very high, where their minimum ultimate tensile strength is valued as high as 1242 Mpa. These fasteners are renowned for having a high tensile strength.

Is Grade 8 or 8.8 stronger?

The similarity in names is purely coincidental and the Metric Class 8.8 is not as strong as the Inch Grade 8. As you can see from the table below, a metric Class 8.8 is the equivalent of a Grade 5, not a Grade 8.

What is the difference between 8.8 and 12.9 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.

Bolt grade explained

Is Grade 8 or 10.9 stronger?

10.9 is an indicator of the bolt's strength, roughly equivalent to SAE grade 8, six notches on the head, very high strength, such as would be used for cylinder heads. 8.8 is more common, roughly equivalent to SAE grade 5, three notches, not as strong as 10.9, but still significantly stronger than grade 2.

Is Grade 8.8 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.

Are 10.9 bolts brittle?

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

Is 10.9 the same as Grade 8?

Class 10.9

This is a metric grading similar to the SAE grade 8 classification, which is used in automotive, and structural industries, as well as in high temp applications. Its strength is near the high end of the grade scale, although there are higher grades and strengths for more specialized fasteners.

What grade bolt is the strongest?

A grade 8 bolt is the highest grade SAE bolt. Grade 8 bolts have a minimum tensile strength of 150,000 PSI. As a comparison, the ASTM A325 bolt is roughly equivalent to the SAE grade 5.

What is the difference between 8.8 10.9 and 12.9 grade bolts?

What is the difference between a 10.9 and 12.9 Bolt? Common metric grades are 5.8, 8.8, 10.9 and 12.9. And each grade has a specific bolt strength. The higher the number the stronger the bolt.

What is the strength of a 10.9 bolt?

Grade 10.9 bolts: As these bolts are most often used in the automotive industry, they are also referred to as 'car bolts'. They are made of boron or carbon steel and have high tensile strength (1040 MPa).

Is 10.9 steel good?

These Carbon Steel 10.9 Bolts are also resistant to corrosion and therefore are used in a wide range of industrial applications such as for construction. These fasteners also have excellent finishing and are easy to install, and are also robust.

Is 10.9 high tensile?

Hsfg Bolts Grade 10.9 belong to the ASTM A324 specification. These are intended for high stress applications because they have high tensile strengths.

Is 8.8 a strong bolt?

The marking "8.8" on a bolt typically refers to its grade or strength. In this case, "8.8" indicates that the bolt has a minimum tensile strength of 800 MPa and a minimum yield strength of 640 MPa. This grading system is commonly used in metric countries to classify the strength of bolts and other fasteners.

What are the strongest bolts made of?

What grade is 12.9 metric bolt?

Grade 12.9 Hex Bolts are high strength bolts with 1100MPa minimum yield strength and 1220MPa minimum tensile strength. Suraj Metal Corporation is a leading manufacturer and supplier of the different types such as the Grade 12.9 Hex Head Bolts and others.

Why are 10.9 bolts black?

Hydrogen embrittlement is likely to occur after electro-galvanizing after tightening, so bolts above 10.9 are usually not galvanized, and the surface treatment is usually blackened or hot-dip galvanized.

What nut to use with 10.9 bolt?

High tensile bolts are usually graded 10.9 and 12.9 (these are popular varieties) and you can match a grade 10 nut and grade 12 nut with these units respectively. You can, however, replace lower grade nuts with higher grade ones without fear of breakage and thread stripping.

Can you weld 10.9 bolts?

If you take a heat treated bolt, such as an SAE Grade 5 or 8, or metric 8.8 or 10.9, and weld on it, you've changed the heat treatment, so you have no idea of the new strength. In addition, there may be residual stresses that could contribute to the stress in the bolt.

What is the strongest metric bolt?

Property Class 12.9 bolts and screws have a minimum tensile strength of 1220 MPa for all sizes. 1220 MPa are roughly equivalent to 175 ksi. These parts are very high in strength. In fact, they're the strongest of all the fasteners we've covered in our inch-series and metric bolt head marking blogs.

Which is stronger 8.8 or Grade 5?

However, as you can see in the following table, both tension and shear are higher in Grade 8 bolts over Grade 5 bolts; in fact over 21% higher in shear and 25% in tension. The same is true in metric when comparing 8.8 vs 10.9.

Is a higher grade bolt better?

Bolt Grade Numbers

Each grade has a specific bolt strength. No matter the system used, the higher number means the stronger the bolt. For most home and automotive applications, you won't need anything more than a grade 8 bolt strength or metric class 10.9.