HomeSkills HubWhich Drillscrew For A Composite Panel
Darren Fleck - Engineering Department | Products Manager
Author: Darren Fleck

Which self-drilling fasteners should I use to fix a composite panel?

  • Read time: 2 minutes
  • Date: 04 May 2021
  • Rainscreen & Façades
When choosing a self-drilling fastener to fix a composite panel there are two features that are essential
  • High thread: a larger diameter thread under the head of the fastener also known as a high thread, which ensures the bonded washer is clamped tightly to the top sheet of the panel, creating a weatherproof seal

  • Free-spin / washer compression zone: to prevent thread stripping in thin materials, while creating a superior seal

Self-drilling composite panel fastener Self-drilling composite panel fastener

Why are high threads important?

Composite panels are made from a thin bottom sheet of metal, a layer of insulation material and a thin top sheet. If there is any loading (weight) on the panel, it can cause the insulation to compress. This causes the top sheet to move away slightly from the bonded washer – a gap of less than 0.5mm can cause a leak. The high thread engages the top sheet of the composite panel ensuring an effective seal even under loading.

What else is important when selecting a self-drilling fastener for composite panels?

As with any application, when choosing a self-drilling fastener, you must consider the build-up depth, substrate depth and the type of materials being fastened. Here are some important points to consider:

  • Fastener length

  • Type of drillpoint

  • Fastener material

  • Head style and shape

See our Kingspan, Eurobond, Tata and Trimo selector guides for further assistance on specifying the correct fastener