Why the Washer Matters in Self-Drilling Screws?

In metal roofing and steel construction, screws do more than connect materials. They also help protect fastening points from water and environmental exposure.

One important component is the washer. Although small, it plays an essential role in fastening performance.

1. What Does a Washer Do?

A washer helps distribute pressure, protect the material surface, and improve the stability of a fastening connection.

When combined with a rubber sealing element, it can also help prevent water from entering through the fastening point. This is especially important for outdoor applications such as metal roofing and steel cladding.

2. What Is a Bonded Washer?

A bonded washer consists of a metal washer and a rubber sealing element bonded together.

The metal part provides support, while the rubber part creates a sealing interface between the screw and the installed surface.

EPDM rubber is commonly used because of its weather resistance, making it suitable for many outdoor fastening applications.

Bonded washers are widely used with self-drilling screws for:

◎ Metal roofing sheets; 

◎ Steel cladding and siding; 

◎ Outdoor metal panels; 

◎ Steel structures

3. How to Choose the Right Washer?

When selecting a bonded washer, consider:

◎ Material: Choose materials suitable for the application and environment.

◎ Diameter: Ensure sufficient contact and sealing area.

◎ Rubber properties: Thickness and hardness affect compression and sealing performance.

◎ Installation: Avoid over-tightening, which may damage the rubber sealing element.

The washer and screw should always be selected as a matching fastening solution.

4. Choosing the Right Fastener Supplier

At Handan Xiaojun Fastener Manufacturing Co., Ltd., we specialize in self-drilling screws and self-tapping screws for various industrial and construction applications.

From hex washer head self-drilling screws to countersunk designs, we focus on product quality and consistent manufacturing to meet different fastening requirements.

Looking for reliable fastening products for your next project? Contact us today!

Email: xj@xj-fastener.com

Xiaojun Fastener — Professional Screw Manufacturer.