In terms of the selection and application of fasteners, it’s necessary to make sure that the aspect of the fastener is suited to the application. In other words, the fastener coating is critical as it will influence both the ease of use and the longevity of the fastener.

2. Types of coating for screws

Zinc

Zinc is one of the most common coatings for it’s cheap and protective. It’s used to protect the fasteners from oxidate damage, such as rusting, etc. Generally, there are two types of zinc coating： white zinc coating (clear zinc coating) and yellow zinc coating.

 

Phosphate

Phosphate coating refers to dipping the fasteners into a phosphate solution. There will be a layer on the surface for medium protection. Like zinc coating, phosphate coating is also a popular type of coating for fasteners. This type of coating is ideal for use in a dry setting, rather than where the fastener is likely to be in contact with a lot of water.

Ruspert

As new processing of metal surface treatment, the Ruspert coating provides high performance of corrosion resistance. This coating includes 3 layers: the first layer is metallic zinc plating； the second layer is chemical conversion film and the third layer is baked ceramic surface coating. With this coating, a 500 to 1000 hours salt spray test result can be guaranteed.

Another advantage of the Ruspert coating is that it can be coated in various colors, such as blue, grey, silver, red, etc. This coating can also be combined with other coatings to achieve more customized requirements.

Dacromet

The Dacromet coating is a mixture of zinc & aluminum powder, chromate, and organic dissolvent with sticky material.  It has good performance of anti-corrosion after coating on metal parts and baked under 300°C temperature. Dacromet has an excellent anti-rust performance, almost 7 times than the electric galvanizing.

As a professional fastener manufacturer, BLUEKIN offers screws with a great variety of coatings.