Breaking strain of 8mm Eye Bolt?

[Stemar]

Jissel is a Snapdragon 24. I've fitted her out with single line reefing running from an eye on the boom, through the leach cringle, back down to a cheek block on the boom. The line goes forward, though a block I'll call B, up to the luff cringle, which has a bock to reduce friction, then down to the foot of the mast and hence to the cockpit. The system works well, but block B is fixed to an 8mm eye bolt that runs through the handle hole for the old roller reefer. The system is duplicated on the other side of the boom for reef 2.

The eye of the eye bolt on reef on has fractured. The breaks are crystalline in appearance and there's no obvious plastic deformation. Was it a casting fault, or is it possible that I've overstressed it to the point of breaking with a small tuphnol winch?

Part 2 is, can I replace like with like, or do I need to beef things up a bit? That gets a bit complicated, as the handle hole won't allow anything bigger.

 

[Tranona]

Was it stainless or mild steel galvanised? Doubt you could break it with just man power, so probably a faulty bit of Kit. I have used both galvanised and stainless eye bolts for the same job, but through the deck for 25 years on a boat with a much bigger rig without any problems.

 

[Stemar]

It claims to be A4 stainless. I wouldn't use galvanised unless there was a good reason to.

Doubt you could break it with just man power, so probably a faulty bit of Kit.

That's kind of what I was thinking. If I'd overstressed it, there should have been some distortion. The replacement claims a breaking strain of well over a ton, and the Hulk I am not!

 

[vyv_cox]

316 stainless steel is ductile and will not fracture in a brittle mode without some corrosion influence. I would expect a good eye bolt to be forged rather than cast but a cheap one might well include flaws.