What is the trace on the surface of the round head slotted machine screws?

When many screw fasteners are produced, there are occasional problems that cause the screws to become defective and cannot be used. The problems with the appearance of these screws generally include thimbles on the surface, scratches, heads, headshots, and the like. So why is there a trace on the surface of the round head slotted machine screws?

There are traces on the surface of the round head slotted machine screws. Generally, there is a problem with the mold. For example, if the mold is broken and the surface of the mold has fine iron scraps, the surface of the screw will be traced.

Some customers will ask for the presence of traces on the head surface of the round head slotted machine screws, as they are used as exterior parts. When the surface of the screw has traces, it looks less beautiful. So they will ask for no traces on the surface of the screw.

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