Performance grade 4.8
Lugs of this grade can be used for assembling ordinary furniture, fixing internal components of household appliances, general lightweight structures, and temporary fixation with low strength requirements.
Performance grade 8.8
This grade of bolts can be used for automotive chassis components, main connections of general mechanical equipment, and building steel structures; it is the most common high-strength grade, used for critical connections that need to withstand large loads or impacts.
Performance grade 10.9
This grade of bolts can be used in heavy machinery (such as excavators), bridge steel structures, high-pressure equipment connections, and important building steel structure connections; they can bear high loads and intense vibrations, and have extremely high requirements for reliability and fatigue resistance.
Performance grade 12.9
This grade of bolts can be used in aerospace structures, high-end precision machinery, and racing engine components; for extreme conditions where weight and volume are critical and where ultimate strength is required.
Stainless steel A2-70/A4-70
This grade of bolts can be used in food machinery, chemical equipment piping flanges, outdoor facilities, ship components; corrosive environments such as damp, acid-base media or high hygiene requirements situations.
Measuring the mechanical properties such as strength and hardness of the bolts is the most crucial basis for selection.
It is represented by numbers or numbers combined with letters, such as 4.8, 8.8, 10.9, A2-70.
Steel bolts: Markings are in the form of X.Y (for example 8.8)
X (the first part of the number): Represents 1/100 of the nominal tensile strength (Rm), in units of MPa. For example, 8 represents Rm ≈ 8 × 100 = 800 MPa.
Y (the second part of the number): Represents 10 times the ratio of the yield strength (Re) to the tensile strength (Rm).
Post time: Dec-29-2025
