ILCA/Laser Mega Bolt
A 10mm diameter pivot bolt for a ILCA/Laser, with 2 x 20mm washers and a nyloc nut, in A4 marine-grade stainless steel. This will fit any ILCA/Laser rudder stock and can help to remove any looseness between the rudder blade and the stock.
If your rudder blade still has a thin bolt and a plastic tube inside the rudder blade pivot hole - and you just can't seem to get the whole thing tight enough - then you can remove the old bolt AND the plastic tube and replace them with this single bolt for a much better connection. No drilling or reworking required. Tighten it to your preferred tension to enable the rudder blade to be retracted and lowered when required.
To make the nut and the head of the bolt low-profile, imperial dimensions are used. So the perfect spanner size is 9/16". Or a 15mm spanner is quite close.