There is always someone needing coffee sacks it seems, so we always manage to pass them on somewhere instead of them being thrown away. I think the instruction makers presume the person making it can not work out which things need a manual screwdriver - obviously the round clamps which grab a bolt you screwed into the other part and then pushed through so it just shows in the circular hole - need a manual screwdriver. I am not however screwing in manually 6cm long self tapping screws - aside from time it's good way to get a repetitive strain injury.