Bo'sun Supplies, Co

[cephius (Dave)]

I needed stainless steal rail hardware for a small improvement project. I found this on-line store was easy to navigate, had good prices, and reasonable shipping costs.I had one part back ordered. They kept me informed and shipped it express when the part came in, at no additional cost to me.Worth a positive recommendation from an experienced on-line shopper.

 

[Brian M H23]

Looks pretty good

Im curious about their "quick-attach" swageless fittings, though. They don't require any untwisting of the wire. they also have a picture on their website of a tensile test of the fittings..and while the numbers look good, the photo is unnerving..it looks like the rope failed because of a stress concentration at the fitting, and it looks like the outer stands snapped and the core is not loaded at all. Odd.

 

[KorculaChris]

Brian,

that wire pulled out at 107% of the breaking strain of the wire...not bad!

 

[Brian M H23]

Yes, but

I'm just a little worried. I can't find any other reviews of the product, and the only place that has done a test is a retailer of said product. Not to forget that in his test, he doesn't even NAME the "baseline" swageless product, but it is apparent;y quite an inferior product if the (unnamed) supplier would send him an assembly that failed a simple tensile test.Nobody else seems to ever mention these "quick-attach" anyway, just norseman, hayne, sta-lock.

 

[sand sailor]

look at the design

it works with the same principal as the swage fittings but its adjustable and reusablei give it a thumbs up from the engineering side

 

[Robert Gainer]

I may have missed something but

Sand Sailor,I may have missed something but from where I am standing the two fittings have very little in common. The swage gets it holding power from the metal in the swage flowing into the spaces between the strands of the wire under the very high pressure of the swaging process. The metal of the wire and the swage are in fact almost fused together and if you cut a swage apart you will have trouble seeing the joint between the two.The Quick Attach depends on squeezing the wire between serrated jaws. Friction is the only thing holding the wire instead of the cold flowing of the swage metal into the wire itself. While this may be good enough it's not the same thing and fatigue life may be compromised because of the distortion of the wire at the clamping surface. They are used on ships and after they get some real life experience I would consider them but not now. I don’t want to be the test case.All the best,Robert Gainer

 

[tcbro]

Brian,

You didn't read far enough into the article. In the yellow panel at the bottom of the story they identified the other swage-less fittings as Norseman and Sta-lock.Toms/v Orion's Child

 

[Brian M H23]

Tom

Thanks, I didn't see that! Looking more closely at the charts, and comparing them to other tensile-test charts, it is pretty clear (to me) that if I do purchase these, I'm going with sta-lok. I don't like how the suncor fitting (bottom chart) holds..holds..holds..gone. That is indicative to me of the wire pulling out of the fitting, not the wire breaking. When steel fails, it stretches, yields (permanent deformation), stretches some more, and then breaks (similar to the performance of the sta-lok fitting).Anyway, assuming that they used the same piece of wire, I also notice that the sta-lok fitting held on while they streteched the wire .55 in, while the suncor at .475. Thats a pretty significant difference!

 

[Robert Gainer]

What you say is true but

Brian,What you say is true and chart one looks like a classic example of yield point and Young's module. But I have two things to say. First you will never stress a rig to that point so I wouldn’t worry and second what you are looking at in the chart may be what Navtec found to be an interesting effect of stainless on stainless in a swage fitting in a series of pull tests they did. Stainless on stainless will gall under pressure. When they pulled some combinations of wire and swage the wire would pull a bit and then tighten up and fail at a higher strain then the first evidence of slipping. That might explain the .030 difference in elongation of the samples between chart one and chart two. Either way you are right and chart two shows a sudden failure before reaching the yield point of the wire.In a practical sense I think the failure mode will be fatigue and not failure from stress so the tests done for the article may be misleading. In real world use I would expect the Quick Attach fitting to fail earlier and at less stress then a swage or either Norseman and Sta-lock.All the best,Robert Gainer

 

[Ken13531]

Thanks for the link

Thanks for the link to a great site.Someone just asked about a boat cover. Here is a quick and easy one to make.I wish I had seen this one earlier.I was interested in buying stainless fittings and found just what I needed here too.