Grade 4.8 Bolts

Bolts with a performance grade of 4.8 have a minimum tensile strength of 400 MPa and a minimum yield strength of 320 MPa. The first number, 4, indicates the minimum tensile strength in hundreds of mega pascals (MPa). The second number, 8, indicates the ratio of yield strength to tensile strength, expressed as a percentage. In this case, the yield strength is 80% of the tensile strength.

These bolts are commonly used in applications where high strength is not critical, such as in light-duty construction, automotive applications, and general purpose use. They are typically made from low to medium carbon steel and are not designed to withstand heavy loads or extreme conditions.

Grade 5.6 Bolts

Bolts with a performance grade of 5.6 have a minimum tensile strength of 500 MPa and a minimum yield strength of 300 MPa. The first number, 5, indicates the minimum tensile strength in hundreds of mega pascals (MPa). The second number, 6, indicates the ratio of yield strength to tensile strength, expressed as a percentage. In this case, the yield strength is 60% of the tensile strength.

These bolts are stronger than bolts with a performance grade of 4.8, but still not designed for high-stress applications. They are often used in automotive and construction industries, where moderately high strength is required but high reliability and durability are not critical.

It is important to note that bolts with a performance grade of 5.6 should not be used in applications where high strength is necessary, such as in heavy machinery or structures that support heavy loads.

Grade 8.8 Bolts

Bolts with a performance grade of 8.8 have a minimum tensile strength of 800 MPa and a minimum yield strength of 640 MPa. The first number, 8, indicates the minimum tensile strength in hundreds of mega pascals (MPa). The second number, 8, indicates the ratio of yield strength to tensile strength, expressed as a percentage. In this case, the yield strength is 80% of the tensile strength.

Bolts with a performance grade of 8.8 are used in applications that require moderate to high strength, such as in structural steelwork, machinery, and automotive industries. They are typically made from medium carbon steel, alloy steel or boron steel, and can withstand higher stress and tension than lower grade bolts.

Grade 9.8 Bolts

Bolts with a performance grade of 9.8 have a minimum tensile strength of 900 MPa and a minimum yield strength of 720 MPa. The first number, 9, indicates the minimum tensile strength in hundreds of mega pascals (MPa). The second number, 8, indicates the ratio of yield strength to tensile strength, expressed as a percentage. In this case, the yield strength is 80% of the tensile strength.

Bolts with a performance grade of 9.8 are used in applications that require high strength and reliability, such as in structural steelwork, machinery, and automotive industries. They are typically made from alloy steel or carbon steel, and can withstand high stress and tension.

Grade 10.9 Bolts

Bolts with a performance grade of 10.9 have a minimum tensile strength of 1000 MPa and a minimum yield strength of 900 MPa. The first number, 10, indicates the minimum tensile strength in hundreds of mega pascals (MPa). The second number, 9, indicates the ratio of yield strength to tensile strength, expressed as a percentage. In this case, the yield strength is 90% of the tensile strength.

Bolts with a performance grade of 10.9 are used in applications that require high strength and reliability, such as in structural steelwork, machinery, and automotive industries. They are typically made from alloy steel or carbon steel, and can withstand high stress and tension.

Bolts with a performance grade of 10.9 provide a higher level of strength and safety than lower grade bolts, such as 4.6, 5.6, or 8.8. In some cases, bolts with a performance grade of 10.9 may be replaced with bolts of even higher grades, such as 12.9, for applications that require additional strength.

Grade 12.9 Bolts

Bolts with a performance grade of 12.9 have a minimum tensile strength of 1200 MPa and a minimum yield strength of 1080 MPa. The first number, 12, indicates the minimum tensile strength in hundreds of mega pascals (MPa). The second number, 9, indicates the ratio of yield strength to tensile strength, expressed as a percentage. In this case, the yield strength is 90% of the tensile strength.

Bolts with a performance grade of 12.9 are used in applications that require the highest levels of strength and reliability, such as in critical structural steelwork, machinery, and automotive industries. They are typically made from alloy steel or carbon steel, and can withstand very high stress and tension.

Bolts with a performance grade of 12.9 provide the highest level of strength and safety among all grades of bolts. They are used in applications that require the utmost reliability and safety, and where failure could have catastrophic consequences.

Performance Grade Minimum Tensile Strength (MPa) Minimum Yield Strength (MPa)
Class 4.8 400 320
Class 5.6 500 300
Class 8.8 800 640
Class 9.8 900 720
Class 10.9 1000 900
Class 12.9 1200 1080