Defender lashing eye bolt, 17mm or 11/16?

Anyone know what the size of this bolt is? I've got a stubborn one covered in layers of waxoyl and other muck, and want to make sure that it's the the muck and not the bolt that I'm mashing as I struggle to tease it off.

Only 2 ways to undo that sort of thing. With a grinder or snap it.

could be either - mine has a random selection.

Oh it's coming undone just very slowly as it strips the waxoyl off. I'm using a 17mm socket on the nut and an adjustable spanner on the nut (as it's all I have in that size) and it's slipping off and rounding down the nut.

If all else fails I'll be grinding it off to get my jate rings on there, but not quite yet.

why don't ye just wire brush them first tae clean them and give them a scoosh of gt85 or wd40? It'd make life a whole lot easier

Ended up doing a combination of everything. Brushed as much of the layers of waxoyl and grim off as I could, then used a newly bought 17mm spanner and some WD40, and my foot to assist my wrench. Got them off in the end - the nuts aren't much use for anything any more but that'll not be a problem for long.