How do the types of bolts and nuts correspond?

The bolt M4 corresponds to the nut M4. For example, the nut of M4-P0.7 can only be connected with the bolts of M4-P0.7 series (in the nut, M4 means that the inner diameter of the nut is about 4 mm, and 0.7 means that the distance between two threaded teeth is 0.7 mm).

Bolts: mechanical parts, cylindrical threaded fasteners with nuts. A fastener consisting of a head and a screw (a cylinder with external threads) needs to be matched with a nut to firmly connect two parts with through holes.

This connection form is called bolt connection. If the nut is unscrewed from the bolt, the two parts can be separated, so the bolt connection is detachable.

Nut is a part closely connected with mechanical equipment. Nuts and bolts of the same specification can be connected together through internal threads.

Extended data

Bolts are divided into ordinary holes and hinged holes according to the stress mode of connection.

Bolts are classified according to the head shape: hexagon head, round head, square head, countersunk head, etc. Among them, hexagonal head is the most commonly used, and countersunk head is used where connection is needed.

Bolts are divided into coarse teeth and fine teeth according to thread types, and coarse teeth types are not displayed in bolt identification. Bolts are classified into 8 grades according to performance grade: 3.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9 and 12.9.

Among them, the bolts above grade 8.8 (including grade 8.8) made of low-carbon alloy steel or medium-carbon steel and heat-treated (quenched and tempered) are generally called high-strength bolts, while the bolts below grade 8.8 (excluding grade 8.8) are generally called ordinary bolts.

Ordinary bolts can be divided into three grades according to manufacturing accuracy: A, B and C. Grade A and B are refined bolts, and Grade C is thick bolts. Unless otherwise specified, the connecting bolts of steel structures are generally ordinary thick C-grade bolts.

The nut specification table unifies all kinds of nuts in detail, and subdivides some specifications of nuts with the table. There are many kinds of nuts, and there are also nuts of different materials.

Each type of nut has different specifications, and each type of screw also has its mechanical properties and functions.

Baidu encyclopedia-bolt

Baidu encyclopedia-nuts