Nuts are parts that tightly connect mechanical equipment. They can only be connected together with nuts and bolts of the same specification through the threads on the inside. For example, the nuts of M4-P0.7 can only be connected with bolts of the M4-P0.7 series (in nuts, M4 refers to the nut with an inner diameter of about 4mm 0.7 refers to a distance of 0.7mm between the two thread teeth); the same is true for American products, for example, a 1/4-20 nut can only be used with a 1/4-20 screw (the inner diameter of a 1/4 nut is about 0.25 inches, and a 20 nut has 20 teeth in each inch)

Stainless steel: self-locking nuts, locknuts, lock nuts, four-prong nuts, screw-in nuts and safety nuts, thin-rod screw connecting nuts, self-locking hexagonal cap nuts, nuts for anchor screws, hexagonal crown thin nuts, and eye nuts.

Fine tooth all-metal hexagonal flange face lock nut, full metal hexagonal flange face lock nut, fine tooth non-metal insert hexagonal flange face lock nut, fine tooth hexagonal flange face nut

Welded square nuts, welded hexagonal nuts, retaining nuts, embedded round nuts

Slotted round nut, side round nut with hole, end round nut with hole, small round nut, round nut, ring nut, butterfly nut

Copper materials: copper nuts, inlaid copper nuts, knurled copper nuts, embedded copper nuts, injection-molded copper nuts, etc

Alloy: zinc-copper alloy nut, etc

The main attributes of nuts include national standard (GB), German standard (DIN), standard (ISO), Japanese standard (JIS), American standard (ASTM/ANSI) and other standards. Among them, national, German and Japanese standards are represented by M (such as M8 and M16), while American and British systems use fractions or # to represent specifications (such as 8#, 10#, 1/4 and 3/8).
Commonly used standards for nuts
GB41 ⅠHex Nut ——Grade C
GB6170 ⅠHexagonal Nut ——Grade A, B
GB6171I hexagonal nut —fine tooth— Grade A, B
GB6172 Hexagonal Thin Nut ——Grade A, B— Chamfer
GB6173 Hexagonal Thin Nut ——Tiny Tooth— Grade A, B
GB6174 Hexagonal Thin Nut ——Grade B— No Chamfer
GB6175II hexagonal nut ——Grade A, B
GB6176II hexagonal nut ——fine tooth— Grade A, B
GB6177 Hexagonal Flange Face Nut —Grade A
GB55 hexagonal thick nut
GB56 hexagonal extra thick nut
GB1229 large hex nut (high strength for steel structure)