I know this is late but it might help someone else. I uses 2 different 1/2 impact guns and flattened sockets but could not shift the bolts on a 4 hour old machine. I ended up using an extended cross brace socket arrangement and lots of umph to shift them. The crossbrace kept the force centered on these very thin headed bolts to stop them rounding.

Hi John,

The bolts require a socket with no leading taper – we actually make these ourselves to be compatible with the bolts used on our chippers. The 16mm hexagonal socket tool can be purchased here: https://forest-master.com/product/hexagonal-impact-socket/. The bolts are fitted with thread lock so you may need to apply reasonable force at first to loosen them off.