Hi Zebe,
As far as we are aware, the thread is M4. For longer screws you could use something like the Easydrive Snap-Off Screws Zinc-Plated 4 x 45mm 100 Pack (5442P). You just break these off at the required length. Alternatively use M4 machine screws of the required length.
Thank you for using Q&A. PB
Answered by: Pebo
Date published: 2019-06-04