What’s the difference between screw, bolt and nut?

(1) bolt:

A type of fastener consisting of a head and a screw (cylindrical body with external thread) to be fitted with a nut for fastening two parts with through holes.This type of connection is called the bolt connection. If the nut is unscrewed from the bolt, it can also make the two parts separate, so the bolt connection is a detachable connection.

(2) screws:

A kind of fastener composed of head and screw can be divided into three types according to their uses — machine screws, setting screws and screws for special purposes.Machine screws are mainly used for fastening connection between a part with an internal threaded hole and a part with a through hole, without nut matching (this connection form is called screw connection, also a detachable connection;It can also be used with a nut for fastening connection between two parts with through holes.Set screws are mainly used to fix the relative position between two parts.Special purpose screws are ring screws for lifting parts.

The best material is 316 corrosion resistant stainless steel, followed by 304.Carbon steel is the next most common material.

The standard of hexagon nut and utility have what

As a standard part, nuts and rivets with pull mandrel have their own standards.Xiaobian on the hexagon nut standard is summarized for the difference and connection and their use.

For hexagon nuts, the commonly used standards are:

GB41 Ⅰ Hexagon nuts — Class C

GB6170 Ⅰ type hexagon nut — A, B grade

GB6171Ⅰ Hexagon nuts — fine tooth — grade A and B

GB6172 Hexagon thin nuts — Class A and B — Chamfered

GB6173 Hexagon thin nuts — fine tooth — grade A and B

GB6174 Hexagon thin nuts — Class B — No chamfering

GB6175Ⅱ type hexagon nut — A, B grade

GB6176Ⅱ type hexagon nuts — fine tooth — grade A and B

GB6177 Hexagon flange nuts — Class A

GB55 hexagon thick nut

GB56 hexagon ultra thick nut

GB1229 Hexagon nuts (high strength for steel structures)

1, ordinary hexagon nuts: widely used, characterized by large fastening force, the disadvantage is that there should be enough operating space in the installation, the installation can use a live wrench, open wrench or glasses wrench, the wrench above all need a lot of operating space.

2, cylinder head hex nut, is the most widely used in all the screws, because its binding force is larger, can use Allen key operation, the installation is very convenient, when used in almost all kinds of structure, more beautiful and tidy appearance, defect is slightly lower than outside hexagonal fastening force, also repeated use can’t remove the socket head broken easily.

3, disk head hexagon nut: rarely used in machinery, mechanical properties of the same, mostly used in furniture, the main role is to increase the contact surface with wooden materials and increase the appearance of the ornamental.

4, headless hexagon nut: some structures must be used, such as the need for a large jacking force of the top wire structure, or the need to hide the place of the cylindrical head.

5, countersunk hex socket nut: mostly used in power machinery, the main role of the same hex socket.

6. Nylon lock nut: it is inlaid with nylon apron in hexagonal face to prevent loosening of thread. It is used in strong power machinery.

7, flange nut: mainly play a role in increasing the contact surface with the workpiece, mostly used in pipes, fasteners and some stamping and casting parts.