Looking at the underside of any mower, the blade rotates ANTI-CLOCKWISE. The blade bolt is a standard right-hand thread - just TIGHT. Get a 6-sided socket (as used on an impact wrench) and use that.
phil_saunders(a)bigfoot.com
Phil Saunders
September 2012
If the blades turn clockwise, looking at blades from underneath, where bolt is. undo the bolt the same. If undo was oposite, they would unscrew themselves all the time
SD
September 2012
I can answer this question...
How do I change blade on Honda Harmony II HRT 216?