The non-metal coating refers to the maintenance layer formed on the surface of metal equipment or parts by organic polymer materials such as paint and inorganic materials such as ceramics, and non-standard anti-theft screws. The maintenance layer can completely isolate the base metal from the environment medium to avoid the corrosion of the base metal caused by contact corrosion on the stainless steel standard part medium. Hex Slotted Bolt so the maintenance layer should have some of the following characteristics:
First, corrosion resistance, wear resistance, high hardness;
Second, the structure is tight, intact and has small pores.
(3) strong separation from base metal and good adhesion;
Four, the average spread and have a certain thickness.
ANSI B18.2.1 matters needing attention in mold material selection:
The material selection of the heading die is very important. This is mainly because the service life depends on the quality of the tungsten steel inside. The non-standard anti-theft screw uses authentic spring tungsten steel to effectively ensure its service life. The washboard needs to have very high hardness, wear resistance, sufficient strength, impact force and fatigue resistance.
The hardness of the working part should be 59HRC. If it is greater than 62HRC, teeth will collapse. If it is less than 59HRC, wear will occur, affecting its service life. Quenched martensite is less than grade 3. There must be no decarburization and low hardness parts on the working surface, and there must be no nicks, cracks and other defects on the surface of the washboard that affect the service performance. Otherwise, there will be a series of problems that will affect the normal use in the later period.