What are the categories of screw hardware? What causes the screws to rust

Hardware screw refers to the screw class of hardware fasteners, but the name is not the same, usually screws, screws, screws, fasteners, standard parts. The type is a lot of people, and different types are applicable to different places, so what are the categories of screw hardware? What causes the screws to rust? Don’t worry, the following nine is hardware network to explain for you, let’s see.

What are the categories of screw hardware?
Generally refers to the standard parts made of metal, which usually includes the following 12 categories of parts:

1. Bolt:

A fastener consisting of a head and a screw (a cylinder with external threads) in two parts, to be fitted with a nut, for fastening two parts with a through hole. This type of connection is called bolted connection. If the nut is unscrewed from the bolt, the two parts can be separated, so the bolt connection is a detachable connection.

2. Stud:

A type of fastener without a head and having only external threads at both ends. When connected, one end of it must be screwed into the part with an internal threaded hole, the other end through the part with a through hole, and then screw on the nut, even if the two parts are tightly connected into a single whole. This connection form is called a stud connection, which is also a detachable connection. It is mainly used for occasions where one of the connected parts is thick, requires compact structure, or is not suitable for bolted connection due to frequent disassembly.

3, screw:

It is also a kind of fastener composed of two parts of the head and screw, which can be divided into three categories according to the use: machine screws, setting screws and special purpose screws. Machine screws are mainly used for the fastening connection between a part with a tight threaded hole and a part with a through hole, without the need for nuts (this connection form is called screw connection, and it is also a removable connection; It can also be used in conjunction with nuts for fastening connections between two parts with through holes.) The setting screw is mainly used to fix the relative position between two parts. Special purpose screws such as ring screws for lifting parts.

4. Nuts:

With internal thread holes, the shape is generally shown as a flat hexagonal column, there are also flat square column or flat cylinder, with bolts, studs or machine screws, used to fasten the connection of two parts, so that it becomes a whole.

5, self-tapping screw:

Similar to machine screws, but the thread on the screw is a special thread for self-tapping screws. Used to fasten the connection of two thin metal components, so that it becomes a whole, the member needs to make a small hole in advance, because the screw has a high hardness, can be directly screwed into the hole of the member, so that the corresponding internal thread is formed in the member. This connection form is also a detachable connection.

6. Wood screws:

It is also similar to machine screws, but the thread on the screw is a special wood screw thread, which can be directly screwed into the wooden member (or part), and is used to fasten a metal (or non-metal) part with a through hole to a wooden member. This connection is also a detachable connection.

7. Washer:

A type of fastener in the shape of an oblate ring. Placed between the supporting surface of the bolt, screw or nut and the surface of the connected part, it has the function of increasing the contact surface area of the connected part, reducing the pressure per unit area and protecting the surface of the connected part from being damaged; Another type of elastic washer can also play a role in preventing the nut from loosening.

8. Stop ring:

It is installed in the shaft groove or hole groove of the machine and equipment, and plays the role of preventing the parts on the shaft or hole from moving left and right.

9. Sales:

It is mainly used for parts positioning, and some can also be used for parts connection, fixing parts, transmitting power or locking other fasteners.

10. Rivets:

A fastener consisting of two parts, a head and a nail rod, used to fasten and connect two parts (or members) with a pass hole so that they form a whole piece. This connection form is called rivet connection, referred to as riveting. Genus and non-detachable connection. Because in order to separate the two parts connected together, the rivets on the parts must be destroyed.

11. Assemblies and connection pairs:

Assembly refers to a class of fasteners supplied in combination, such as a machine screw (or bolt, self-supplied screw) and flat washer (or spring washer, lock washer) combined supply; Connection pair refers to a special bolt, nut and washer combination supply of a class of fasteners, such as steel structure with high strength large hexagon head bolt connection pair.

12, welding nails:

A heterogeneous fastener composed of a nail rod and a nail head (or no nail head), which is fixed on a part (or component) by welding method in order to be connected with other parts.

What causes the screws to rust?
1, electroplating factory in the plating of metal screws, drying did not dry, resulting in residual water vapor. Or after drying in the packaging when condensate formation. Lead to chemical reactions, resulting in undesirable occurrences, resulting in rust of hardware screws.

2, long-term storage in wet places, for a long time, hardware screws are slowly corroded, oxidized, resulting in serious rust.

3, when electroplating metal screws, electroplating is poor, and the electroplating is too thin. It causes rust. To sum up, analyze the reasons from four aspects.

These four directions are:

1, storage environment 2, plating type 3, preservation method 4, use environment.

Improvement measures: Storage environment: must put the hardware screws in a suitable environment, should not be too wet, should be ventilated, ventilated, there should not be too much moisture. There should be a bracket to hold the hardware screws, not touching the floor. Plating type: Plating color with longer salt spray test time should be selected. Electroplating should be electroplated well, and the plating layer should not be too thin. The storage method and storage environment are similar, can not be placed in wet places. The use environment, also similar, can not be placed in salinity, acid, salty, high corrosion, high temperature, high humidity environment.

Post time: Jul-02-2024

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