What kind of problems often appear head fasteners?

The fastener is also known as the standard, for the name, we know that, but many manufacturers in the production of fasteners is often overlooked some problems, resulting in fasteners produced in the final scrap, such as fasteners in the head when it is prone to problems, if not reasonable will cause the fastening is not normal use, the fastener head often appear what problem?

1, eccentric:two bad installation and adjustable improper machine.

2, a poor installation and punching head machine properly.

3, the head is not round: the improper choice of a die or a molding is not enough.

4, mold crack: Die rupture or die R angle is not correct, so that the mold was hit by two.

5, the head of a double layer: a bad molding.

6, a red flash: poor forming standard parts head: mainly between punch and die hole clearance is too large or too short by red bars.

7, crack angle: punch needle rupture or two punch and punch is not heavy.

8, head cracking: material problems, must use special potion of metallic materials by rigorous testing, when necessary use heating equipment for heating wire or die a little; use the error such as pan head for six Jiao washer head a die, and the viscosity of the lubricant failure etc..

9, the head forming black film formed on the surface and difficult to remove: stainless steel surface black film can be used to remove liquid erosion, erosion cutting, chemical polishing method can also be used to remove the surface black oxide film.