Standard parts screws include bolts, screws, studs, nuts, machine screws, self-tapping screws, washers, pins, rivets, and retaining rings. It is a basic part that is widely used in various aspects, and its function is to fasten the joint. The coupling form can be divided into a detachable coupling (coupling with threaded fasteners such as bolts, nuts, etc.) and a permanent coupling (using rivets).
How do you distinguish between stainless steel screws, galvanized and nickel-plated screws?
First by color:
Stainless steel is the primary color of iron.
Galvanized screws are white, colored, and black.
The nickel plated screws are silver.
1. Stainless steel screws are made of stainless steel. The color of stainless steel is mainly iron and carbon alloy, so the color is close to the color of iron;
2. The surface of galvanized screws is galvanized with white zinc, colored zinc, black zinc, etc., so the color of galvanized screws is generally white, color, black;
3. The color of nickel-plated screws is related to nickel, generally showing a very bright silver.
Different methods of distinguishing stainless steel screws, galvanized and nickel-plated screws
1. Distinguish by magnet: stainless steel does not have magnetism under normal conditions. Stainless steel screws can not be absorbed by magnets. Zinc-plated and nickel-plated screws can be adsorbed by magnets.
2. Distinguished by oxidant: metal nickel has a strong passivation ability, when the plating can quickly form a very thin passivation on the surface, so the surface of the nickel-plated screw has a passivation film, the galvanized surface is a layer Zinc, stainless steel has no surface and can be distinguished by strong oxidizing agents.
3. Distinguish by strong acid and alkali: stainless steel contains chromium and nickel, has strong anti-corrosion performance, is not corroded by strong acid and alkali, has a passivation film on the surface of nickel-plated screw, and is slowly eroded by strong acid and alkali, galvanized screw Being eroded the fastest.