Can anyone help me identify what size nuts I need to source and where from.

They are on my alfa axle diff housing and used to have a tab washer, but I’m gonna replace with nyloc.

The axle has normal metric threads on some parts, so I believe these will be metric fine?

Spanner size 14mm, bolt outside diameter is just under 8mm, nut inside is 7mm. Are they 8mm metric fine or what?

Possibly metric fine, just under 8mm, could be 5/16 unf.

Best thing to do is invest in a thread gauge Clarke Quality Thread Pitch Gauge Internal External Screw Mertic 60 degree

Get a Zuess chart as well as the thread gauges to help identify threads

What a dummy I am, your reply's jogged my memory about my 30 year old tap and die set, just wire brushed all the rust of a tap that fitts and it's 8 x 1.0 , now to order some.

Cheers for help.

I would expect they should just be standard M8x1.25 just try a standard M8 nut on with your fingers,
If the thread looks very fine they could be M8x1 or much less likely on an Italian car 5/16" UNF.

Thanks, I’ve sorted it now. Metric fine, 8 x 1.0