What problems often occur when we perform maintenance on fasteners?

1. When the fasteners are quenched, use aluminosilicate cleaner to remove the residue on them, and then wash them carefully to avoid leaving residue on the fasteners, which will affect its normal use. 

2. After the fasteners are tempered, it is very likely that their color will change greatly. After the fasteners are immersed in medical ether for a period of time, a thick substance will form, and this will appear. This situation indicates that the fasteners are not neat enough. After analysis, it will be found that the fasteners are not deposited very effectively when heated, and there may be some slight oxidation of the fasteners in the quenching fluid.

3. If there is pure white substance on the fastener, it may be some phosphide. The reason for this situation is that acid and alkaline cleaning equipment was not used for cleaning, and the dip tank was not inspected carefully enough.