Roni,
There may be more than one supplier out there for metric bolts which could be used for the prop. I had to sort through this also when I got to looking for prop bolts.
For the metric bolt sizes. The Length (80mm) is the total lenght of the bolt shank including the threaded and non threaded part. The lenght of the threaded portion is standardized so if you get an 80 MM bolt, the threaded portion is not mentioned, but is assumed to be the same number of threads as other 80 mm bolts.
The pitch is determined by Rotax as that is what the prop flange is threaded for.
The hardness for metric bolts will be 8.8, 10.9 or 12.9. The hardness is critical as bolts which are too hard carry some risk of cracking in certain applications. 8.8 is medium carbon steel, quenched and tempered. The harder bolts have a slightly higher yield strength and tensile strength, but they are also more brittle.
The other thing a person can run into with metric bolts is stainless steel.....not to be used for this but easily identified as the heads have an "A" embossed on the top
I ended up getting bolts from Fastenall - don't know if they distribute in Canada or not but I bet there is someone who does.
One thing to always check for, due to washers, and other items affecting thickness of the prop hub stack, is to assure that the bolts do not bottom out on the unthreaded shank of the bolt against the engine prop flange.
The other thing I found out is it is hard to find any metric bolts with drilled heads for safety wire, consequently, I believe most folks use jam nuts on the back of the prop hub for securement.
Fly well,
DS