What grade propeller bolts

Muray -

There are quite a few different lock nuts (differing in height & lock system)

Go to good nut & bolt supplier and ask what options they have to suit M8.

AND / OR

Check out the aviator suppliers - they have regular & low profile nuts (mostly imperial but you may be lucky)

I used "Cone" locknuts on my Zephyr prop bolts for over 10 years and some 600 hrs, without any issues.

After torquing apply a witness paint so that you can visually check for loosening.

• Castellated nut.
• Distorted thread locknut.
• Centerlock nut. ...
• Interfering thread nut.
• Tapered thread nut.
• Jam nut.
• Jet nut (K-nut)
• Keps nut (K-nut or washer nut) with a free-spinning washer. ...
• Plate nut.
• Polymer insert nut (Nyloc nut)

Thanks Sean,

The drive lugs in the spacer are the metric M8 threaded rotax lugs the same as in the prop hub, if there is a self locking version of that would be nice but I haven't seen them listed anywhere

My Whirlwind composite ground adjustable prop just uses Nordlock washers and no locknuts of any kind, per the Whirlwind factory instructions.

Thanks James,

Glad to see a propeller manufacturer using this method. I will use the same method