Difference between special screws and standard screws

An ordinary screw is a tool that uses the physical and mathematical principles of circumferential rotation and friction of the inclined surface of an object to gradually tighten the utensils. The installation names of screws are: machine screws, self-tapping screws, drill tail screws, wallboard screws, fiberboard screws, wood screws, hexagonal wood screws, non-stick screws, combination screws, mini screws, furniture screws, electronic screws, chain screws.Special screw, Screw manufacturers in our industry are generally called non-standard screws, also known as special screws and custom screws. Literally, it is a unique screw. In other words, there is no ready-made non-standard screw that is different from the national standard screw, or it can be said to be a special-shaped screw or an odd-shaped screw. Generally speaking, ordinary screws are not suitable for special occasions, and a special screw needs to be designed to match it.

Compared with standard screw fasteners, special screws show superior characteristics in many aspects. In the face of huge market demand, in order to keep up with the development of the times and the pace of social development, special screws are very good weapons. Because the special-shaped screw is only applicable to a certain enterprise or a certain product, it is single and exclusive. In production, the production process is also different from standard screws.

Moisture-proof methods for special screws: 1. For example, special-shaped screws used in vibration machinery should be coated with solvent-free paint as much as possible; 2. Impregnating varnish without oxidizing components, such as epoxy urethane or undenatured epoxy impregnating varnish, 3. When melamine alkyd impregnating varnish is used, the curing temperature and curing time of non-standard screws should be adjusted. The curing temperature should be slightly higher than 130 and the curing time should be longer than 180min, and to strictly implement the process, especially in the hot and humid season, because the paint drying (curing) time specified in the paint factory samples is not necessarily sufficient, and the motor has a specific internal shape. Tips for controlling the plating quality of non-standard screws The quality inspection of special-shaped screws is generally considered from the appearance and the quality effect of plating, measured by the plating quality and corrosion resistance of non-standard screws, and then the appearance of non-standard screws. Corrosion resistance is that we first set the test conditions, and then its corrosion test.

     Special screwThe quality of electroplating should be controlled from the following two aspects: 1. From the appearance of electroplating screws, the surface of the product is not allowed to have local uncoated, burnt, rough, ash, peeling, peeling and obvious stripes, pinholes, black plating slag, loose passivation film, cracks, peeling and serious passivation marks. 2. The coating thickness of the electroplated screw, the coating surface should be smooth and uniform in thickness. The service life of the fastener in the corrosive atmosphere is proportional to the coating thickness. The general economic electroplated coating is 4 ~ 12um, and the standard average thickness of the hot-dip galvanized screw is 54um.