Conventional self tapping screw production complete process
Screws are used in mass quantities in electrical appliances, furniture, automobiles, construction and other fields, the use of very large. How do you mass-produce screws? First of all, briefly describe the complete process from finished product to packaging of self-tapping screws:
The screw production equipment required by the whole screw production process can be roughly divided into: wire drawing machine, cold heading machine, tooth rubbing machine, etc. The production process is specified as follows:
- Screw production process – drawing: also known as drawing wire, pumping wire to cold heading machine. Generally, there is also a process is pickling before wire drawing, in order to remove the oxide film on the surface of the wire, so that the surface of the phosphate film, as far as possible to reduce the rough appearance of the wire and debris on the mold abrasion. After pickling, the wire tray is cold drawn by the wire drawing machine. Suitable for large screws, nuts, self-tapping screws required length of wire.
Two, screw production technology – forming
For ordinary self-tapping screws, the first is to head forming, generally after a die two punching process. Head forming can be countersunk head, round head, large flat head, outer hexagon, inner hexagon and so on;
(1) Cutting: The wire stuck in the cutting die is cut into the required blank material after the movable scissors move in one direction.
(2) One punch: the die is fixed, and the head of the product is formed by a punch, so that the next stroke can be thoroughly formed. When the product is a word groove, a die for concave, oval groove, product is a cross groove, a die for concave square groove.
(3) Two punching: after a punching, the punching has all the work, two punching die moves to the front of the punching die, but also two punching die forward work, the product end molding. After that, the embryo is pushed out by the back punch bar.
Three, screw production technology – rubbing teeth
Generally, the self tapping screw embryo is made into thread, which requires two teeth plates, one tooth plate is fixed, the other rolling semi-finished product is moved, and the product is plastic deformed by kneading to form the required thread. In addition, if the nut is tapped by tapping – tapping teeth.
Four, screw production technology – heat treatment
Self-tapping screws as hardness requirements of the screws, heat treatment is necessary, so that the surface hardness and core hardness of self-tapping screws can meet certain requirements, in order to smoothly tap holes and not too soft.
Five, screw production technology – surface treatment
Appearance disposal is a certain way to form the process of covering layer on the surface of the workpiece, its intention is to give products beautiful appearance, corrosion prevention, appearance disposal methods come down to the following methods: electroplating, hot dip galvanizing, mechanical plating, etc. Commonly used electroplating are galvanized, black/white nickel, black, phosphating and so on.
Finally, after the first five processes are finished, self-tapping screw products out, of course, also have to carry out the screening and drying of defective products. After that, it’s time to package and label the goods for delivery.