What is ... the drilling performance?
The drilling performance of a screw refers to the drill point and defines the maximum thickness of components which can be penetrated with this drill point. The drilling performance value ≥ t is stated in millimetres.
For direct bearing surface (e.g. trapezoidal profile to steel substructure) the following formula can be used:
Drilling performance for direct bearing surface
t = component tI + component tII
For sandwich panels the following formula applies:
Drilling performance for sandwich panels
t = component tII
If the drilling performance (alternatively also called drilling capacity) is too low, the screw cannot finish the work step "drilling" and the drill point clogs with the flowing swarfs. Regarding the drill point diameter and drill point length, self-drilling screws with higher drilling performance are only designed for components of greater thickness. Using self-drilling screws with too much drilling performance in thin components leads to a huge weakening of the holding force and is not permitted.
You can easily determine the drilling performance of EJOT self-drilling screws yourself by having a look at the screw disignation: For example, an EJOT self-drilling screw JT3-6-5.5 has a maximum drilling performance of 6 mm, a JT3-12-5.5 has a maximum drilling performance of 12 mm.
For direct bearing surface (e.g. trapezoidal profile to steel substructure) the following formula can be used:
Drilling performance for direct bearing surface
t = component tI + component tII
For sandwich panels the following formula applies:
Drilling performance for sandwich panels
t = component tII
If the drilling performance (alternatively also called drilling capacity) is too low, the screw cannot finish the work step "drilling" and the drill point clogs with the flowing swarfs. Regarding the drill point diameter and drill point length, self-drilling screws with higher drilling performance are only designed for components of greater thickness. Using self-drilling screws with too much drilling performance in thin components leads to a huge weakening of the holding force and is not permitted.
You can easily determine the drilling performance of EJOT self-drilling screws yourself by having a look at the screw disignation: For example, an EJOT self-drilling screw JT3-6-5.5 has a maximum drilling performance of 6 mm, a JT3-12-5.5 has a maximum drilling performance of 12 mm.
