Screws can be divided into three categories according to their use

Screws can be divided into three categories by purpose: machine screws, set screws and special purpose screws. Machine screws are mainly used for a fastened connection between a part with a fixed threaded hole and a part with a through hole, without nut mating (this connection form is called screw connection, which is also a detachable connection; it can also be It is used in combination with a nut for a fastened connection between two parts with through holes.) It is also the most common screw.

Set screws are mainly used to fix the relative position between two parts. We call it a "stop screw" as the saying goes, and its function is equivalent to that of a positioning pin.

Special purpose screws such as eyebolts are used for lifting parts.

Carbon steel bolts are classified into more than 10 grades, including 3.6, 4.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9, 12.9, etc. Grade, the numbers before and after the decimal point represent the nominal tensile strength and yield ratio of the bolt material respectively. For example, if a bolt with grade 8.8 is marked, the tensile strength of the material reaches 800MPa, and the yield ratio of 0.8 means that its yield strength reaches 800X0.8=640MPa Welcome to inquire about limited purchases.