what is the screw which holds the blade L/H R R/H thread?

yeah...I think he means undo it the regular way...anti-clockwise!

pleasant
June 2013

The direction of rotation will determine the handedness of the thread. The rotation will always be trying to tighten the screw.

For cost & convenience a designer will usually attempt to specify r/h thread and avoid l/h.

It would be a rare thing for your mower whatever the make & model to be any different to any other mower.

Peccavi
June 2013