https://e3d-online.zendesk.com/hc/en-us/articles/4415901401489-V6-Maximum-Temperature-Ratings Any one know why E3D is saying "WARNING: Hardened steel nozzles are not suitable for use with aluminium blocks above 240°C. You will need to upgrade to a plated copper block and hot tighten at 300°C. " i had belived hard nozzle steal/others work fine with aluminium blocks? that being said i have had many leaks with Hard nozzles(steal/tungeten carbide) and aluminium blocks in the past if this is true then that could explain a lot.