David Hearn wrote:
The manual says not to use the standard 13mm chuck with the SDS drill when
in hammer mode. What is the actual problem with doing this? A standard
chuck can cope with basic hammer drills - is it the heavier force from the
SDS drill that could be a problem?

On my Stayer SDS the standard chuck adapter is built so that it
disables the hammer action when you use it.

--
Chris Green