How To Clean Stainless Steel Non-standard Screws?

How to clean stainless steel non-standard screws?

During normal production, the surface of stainless steel non-standard screws is often stained with oil and scale. If the cleaning level is not up to standard, it will affect subsequent use performance. In particular, the magnetic residue generated during the processing process is very likely to disrupt the precise assembly of electronic equipment if not specially treated.

Degreasing and cleaning is the first step

For newly manufactured screws made of non-standard stainless steel, it is recommended to use a weakly acidic degreaser to clean them. This type of degreaser has good ability to penetrate and disperse oil stains, and can quickly decompose the grease on the surface and the residue left by the cutting fluid. During operation, the screws can be immersed in degreasing liquid in the range of 40 to 50 degrees Celsius for 5 to 8 minutes, and then coupled with ultrasonic vibration, the effect will be more thorough.

After the cleaning operation, the surface of the screw will appear clean, but it still needs to be rinsed twice with clean water to remove the residual degreaser. This process step cannot be omitted, otherwise new contamination may be derived in subsequent processes.

Descaling and cleaning

During the heat treatment or cold heading process, a layer of oxide scale will be generated on the outer skin of stainless steel screws. It is recommended to use a specially designed cleaning agent with moderate acidity when performing treatment. This cleaning agent has a strong removal ability for oxide scales and carbides on surfaces with complex structures. Place the screws into the fluid storage tank of the cleaning equipment and soak them for 10 to 15 minutes at a normal temperature.

After the cleaning operation, a passivation film will be formed on the surface of the screw, which can significantly improve the salt spray resistance of the screw. The data obtained from the test shows that the treated screws can withstand 72 hours in a 5% salt spray environment without rusting.

Grinding and polishing

To obtain a bright and beautiful surface, you must use a special grinding and polishing fluid for stainless steel non-standard screws. This fluid is weakly acidic and viscous and has a good polishing effect on the screw surface. Put the screws and polishing fluid together into a vibrating polishing machine and process for twenty to thirty minutes. The surface of the screw will show a uniform metallic luster.

When polishing, the polishing fluid will remove the tiny burrs on the surface, making the screw threads smoother. This will not only enhance the appearance, but also improve the smoothness of installation.

Magnetic removal step

There is a possibility that stainless steel will become magnetic due to cutting and grinding during processing. This situation is a hidden risk for screws used in precision instruments. Based on this, it is recommended to add demagnetization to the cleaning process. Use a demagnetizer to demagnetize the screws. After demagnetization, the magnetic induction intensity retained by the screws should be less than 0.3 millitesla.

Demagnetization is usually carried out after polishing, and then the screws are placed on the conveyor belt of the demagnetizer, and pass through the magnetic field area at a speed of two meters per minute, so that the magnetism can be effectively removed. This step is particularly important in the electronics and medical device industries.

Thorough washing and hot water soaking

After chemical cleaning and polishing of screws, there will be a small amount of chemical residue on the surface, which must be thoroughly rinsed with running water. It is recommended to use deionized water for two rinses, each lasting 3 minutes, to ensure no residue. The screws should then be soaked in hot water of 80 to 90 degrees Celsius for 30 seconds to speed up surface drying.

Residual stains can be softened by soaking in hot water, making the next process easier. In the actual operation process, many factories will implement mechanical drying immediately after this step to prevent water stains from remaining.

Mechanical drying and quality inspection

The last step is to place the cleaned screws in a centrifugal dryer and spin them for 2 minutes at a speed of 1,200 rpm. After drying, there are no water droplets on the surface of the screws, and they can be packaged directly or enter the next processing step. 5% of the screws are randomly inspected every day to conduct appearance and magnetic testing to ensure that the cleaning quality reaches standard status.

As a manufacturer, we have many years of experience in customizing screws. Whether they are made of stainless steel or other materials, we can produce them according to drawings or samples, thus providing comprehensive fastener solutions.

After reading this article, how to clean stainless steel non-standard screws by magnetically removing stainless steel? Have you ever encountered the problem of magnetic residue when cleaning stainless steel screws? Welcome to share your experience in stainless steel processing magnetic removal stainless steel processing magnetic removal in the comment area, like it and forward it to friends who need it!