Introduce The Common Types And Forming Processes Of Screws

1. Types of commonly used screws

The types of screws can be divided according to tooth type, head type, slot type and washer

1. According to the tooth type of the screw, the screw can be divided into mechanical screw and self-tapping screw. Mechanical teeth screws can be divided into metric teeth and inch teeth. Metric teeth are often marked by the outer diameter of the screw, such as M2, the unit is mm, and the pitch of the thread can be added later. When the pitch is the default pitch, it can be omitted. Imperial teeth, the unit is inches, such as 6#-32. Self-tapping screws are divided into single teeth and double teeth. Single teeth are generally used for the connection between metal parts, while double teeth are used for the connection between plastic parts.

2. According to the head type of the screw, the screw can be divided into flat round head type, flat round head type, spherical central column head type, salad head type and hexagonal head type screws.

3. According to the groove type of the screw, the screw can be divided into a flat groove type, a cross groove type, a / cross groove type, a rice groove type, a plum groove type and a hexagonal groove type screw. Torque testing of 1/Phillips screws requires a 1/Phillips torque driver bit.

4. The screws can also be classified according to the different washers they carry. The role of the elastic medium: to provide a pre-pressure to effectively prevent the screws from loosening. screw manufacturers

Second, the commonly used screw forming process

The common processing technology of screws is divided into five steps:

1. Prepare wire, usually bought wire

2. Use a cold heading machine to punch out the head shape and groove shape of the screw

3. Use a thread rolling machine to roll out the threads of the screw

4. Heat treatment of screws

5. Electroplate the screws, usually galvanized, nickel, tin, etc.

The main shape features of screws include: screw head, groove, effective tooth area, toothless area, and beam tail.

The screw is a screw embryo before rolling, and the processing technology of the screw embryo is mainly divided into three steps:

1. Cut material, mainly cut out a certain length of wire

2. One punch, punch out the approximate shape of the screw head and bundle tail

3. Second punch forming, final forming of screws There are two main processing techniques for the end of screws: cold heading machine and thread rolling machine

There are three forming processes for the slot of the screw:

1. The mold is directly processed and formed, with high efficiency and fast processing, and the processed groove is easy to form an outer eight-character

2. The milling machine has a standard groove shape and is beautiful, but the processing is slow and not suitable for mass production.

3. The automatic groove cutting machine has high processing efficiency and is prone to burrs