Why the M8 machine screws broken

Today, a customer told us that they bought a batch of M8 black machine screws from the previous supplier. But these machine screws broke when use. So his customer rejected his batch of goods and demanded compensation. Now All of the 100,000 screws are stored in the warehouse, Find us and ask for the specific reasons and re-purchase a batch from us.

We then feedback the customer’s problem to our R&D dept immediately, and the engineering analysis of possible problems is as follows

1. In order to save costs, the customer’s previous supplier used second-hand cheap materials, resulting in a lot of decline in screw quality.

2. The hydrogen embrittlement reaction of high-strength carbon steel screws occurred during electroplating, and the supplier did not remove hydrogen during the electroplating process because of insufficient professionalism. The brittle fracture of fasteners due to hydrogen embrittlement generally occurs Suddenly, it is unpredictable, so the consequences of this failure form are very serious. Especially when safety performance is required, it is necessary to reduce the generation of hydrogen embrittlement.

So we tell our customers that we will have the following solutions
1. It is recommended that customers use SCM435 material, this material is the best material in carbon steel, and the hardness can also meet customer requirements
2. We recommend dacromet finish and We will definitely remove hydrogen during electroplating to prevent the anti-hydrogen embrittlement reaction.

Finally, the customer paid the mold fee for proofing with us. After the sample was received, the customer was very satisfied and started to cooperate with us.

If you have a custom screw problem that cannot be solved, please feel free to contact us