I hate to do this...but

Hardness and strength have a direct relationship. If using a sensible system, Brinell or Vickers, dividing the value by five gives the strength in tons/in.sq. Rockwell is useless for this purpose. Doesn't work for anything that is surface hardened but fine for through-hardened.

Bisplate 80 is quoted in their brochure at a minimum tensile strength of 690 Mpa. Again, hardly high tensile
 
Hi Tensile steel

Actually Bisalloy quote Bisplate 80 as having a Tensile Strength of 790-930 MPa with an average of 830 MPa but a 0.2% Proof Strength of 690 MPa. And I cannot think why I think its important but I am sure Tensile Strength and a 0.2% Proof Test are different. Again from memory 316 Stainless, Tensile Strength is around 500 MPa - hardly the same strength as Bisplate 80 (and the stainless fittings on our yachts). I'm not sure about RSJs (not sure that we use many of them on yachts - but its good to know that (as we use them for high rise buildings) they are also strong). But then maybe 300MPa difference does not matter and ASTM 514a producers sell product at high prices, and customers pay, all because its a way to pull the wool over the eyes of naive endusers like me. Amazing!!

But good to know the relationship between hardness and strength - so presumably you will be able to confirm that the hardness information that was 'withdrawn' that I recall showed Rocna shanks at 3-4 times less than ASTM 514a are an accurate indication of the steel used in those particular anchors - and it certainly was not anything near the quality of ASTM 514a?

However that does not answer the question, Lewmar claim to use High Tensile steel for their Delta (and have done for over 2 decades), Manson claim to use High Tensile Steel for their Supreme, Anchor Right claim to use High Tensile Steel for their Excel, Holdfast claim to use High Tensile Steel for their Rocna and we have now been discussing it for weeks - why the criticism now?
 
VYV
The terminology in reference to the steel qualities are made for the benefit of the readers and as so not to confuse all, my terminology of the steel is said using the Mr . C terminology, he has educated all as to his high strength—high tensile steels being used in his rickety anchors, his words, so maybe you should have corrected Mr. C as you have been on these forums for so long, why should I confuse the readers with terminology that most would not understand, possibly Ito do not understand, if what you are saying is true then I to stand to be corrected.

High tensile, right or wrong is the common terminology used for steel strengths over and above mild steel,you describe various grades of mild steel, there are three grades available in Australia, I don’t muck around with figures just use the highest grade of mild steel, grade 350 they call it, what the properties are doesn’t concern me ,all I know it is far stronger than the first two grades, doesn’t snap of welds , is easy to use, more importantly grade 350 more than achieves the proof loads that are required for S/H/H/Power in our Super Sarca designs.

The Sarca Excel, because of design requires thinner shanks to achieve correct balance, bisalloy , bisplate 80 whatever you want to call it was tested against mild steel for its strength property’s, over a given length of steel same thickness, the bisalloy began deflecting approx. for times the load that of the 350 grade mild steel, that is how we determine the materials we need to maintain strength when going to a thinner anchor shank.

The advantages and disadvantages of these two steels in anchor design are.

If you bend a mild steel shank it may be possible to straighten or partially straighten so you can redeploy the damaged anchor, welding is very straight forward, if you bend a mild steel shank a solid blow with a hammer can do wonders, bisalloy 80 has great flexing properties, similar to that of spring steel, because of this flexing you have less chance of bending the shank, any steel that flexes is most definitely very difficult to straighten, a solid blow with a hammer will result in the hammer recoiling rather than straightening, and as mentioned pre heating is a must before welding.

I think all of this is fairly irrelevant as to my last post, there are several clear points that I make, your comments and all of the above takes nothing away from what is highly probable, the lid as you call it would never have been taken of in the first place, if the Rickety camp had put the young bloke to bed earlier, then spent some time educating him as to how to keep the lid on, then I would not have to be educated as to what high tensile steel is.

Dubangi you are also correct, even bisalloy 8o does not galvanize as well as350 grade mild steel, if you can recall whale boys test, yet not proven, first thing he reported was the galvanizing was quite exceptional? After all of the above and Steve still claims to have 40 percent more holding power over any anchor tested against, as we know, this is totally untrue, I am sorry if I sound cynical, skeptical? Are they the right words, not sure, but I do know what goes into our anchors.

Thank you for your comment VYV as I will endeavor to be more precise should I decide to post any more threads in relation to steel terminology.

Kind .
Regards.
Rex.
Anchor Right Australia
 
Djbangi said:
And I cannot think why I think its important but I am sure Tensile Strength and a 0.2% Proof Test are different.
Click to expand...

Tensile Strength normally means Ultimate Tensile Strength (UTS) which is the nominal stress at which the material goes bang. In practice yield is the often more important, and the 0.2% proof stress is the stress required to give the material 0.2% of plastic (irrecoverable) strain.

Short version: UTS is the stress which breaks the material, Proof is the stress which permanently distorts it.
 
Grant,

I'm curious about the Rocna QC system.

We are constantly fed grand sounding statements which are obviously designed to make Ronca look like a major multi national

    • [*]"we’ve invested heavily into our own quality control program and have an incredibly robust process. Every single anchor is inspected by trained quality control staff"

      [*]"we do tests with our own people to further validate...."

      [*] "our global quality assurance programme"

      [*]"our team in China"

      [*]"shows a photo that our quality assurance team took during one of their inspections"

      [*]"This process is managed by Rocna staff based in China"

It sounds wonderful and creates the impression of dozens of Rocna's own staff busily ferreting around the Chinese factory making sure that everything is done to the highest standards.
Of course, if you set this against the recent statement that "we're only a small company so it will take some time to correct the website" it does seem to have a credibility gap.

So, what's the reality?
Teams of professionals, recruited from NASA, who guarantee perfection at every stage?
Or a spotty youth in Auckland, occasionally filling out a QC form in between his morning cups of coffee?
 
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Djbangi said:
However that does not answer the question, Lewmar claim to use High Tensile steel for their Delta (and have done for over 2 decades), Manson claim to use High Tensile Steel for their Supreme, Anchor Right claim to use High Tensile Steel for their Excel, Holdfast claim to use High Tensile Steel for their Rocna and we have now been discussing it for weeks - why the criticism now?
Click to expand...

My comments, not criticism, follow from what I wrote in the thread that has been pulled. I looked at the other forum for the measured values but they also appear to have been removed, pending completion of the testing.

I am simply concerned that we are being told that certain properties of anchors, Rocna in particular, are in some way deficient by the use of wording that is in itself inaccurate or inappropriate.
 
Hi rigger,

Cannot agree with you more, you know I have got go in for a triple by-pass soon, serious stuff, no joke, but if the hospital staff are half as clinical as hold fast, then I am sure my survival rate could be considerably higher than that of the standard prep I might escape rigger mortice.

Rex.

Anchor Right Australia.
 
Thanks all for an interesting discussion of metallurgy - I've learned a lot. The different technological balances that have to be maneuvered between strength and flexibility, weight distribution, welding technique and so on seem like a perfect illustration of the concept used in biology of sub-optimal designs. This is where a system appears to be less than perfect, but on balance is as perfect as it can be. An example might be the size of the human brain. Since it would be better for us all to be smarter (some more than others), our brains should be bigger and that would be adaptive. However, if our brains were any bigger, they would literally overheat from the immense blood supply required, so our skull shape would have to change. But change that, and you wouldn't see as many live births. In other words, the sub-optimal design of a smaller brain turns out to be the best design of all.

How this whole discussion affects the average boater regarding something that seems simple, like an anchor, but isn't is the observation that if you can't trust the manufacturer to deal fairly and tell the truth, you can't possibly be expected to sort out all the design issues and make an intelligent choice since you can't get the facts. And if there is one thing I have learned about Rocna so far, is that getting facts from them that are reliable is mission impossible and when you do, many appear to be made up, so how could anyone buy their product?

For an illustration, here is a photo of how the 'high tensile' shank of a Rocna performed under load. I'm not sure if this is a special design made by Rocna for anchoring around corners, or an illustration of why buying from some manufacturers has a great deal more risk to it than buying from others.
 
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Delfin said:
For an illustration, here is a photo of how the 'high tensile' shank of a Rocna performed under load. I'm not sure if this is a special design made by Rocna for anchoring around corners, or an illustration of why buying from some manufacturers has a great deal more risk to it than buying from others.
Click to expand...

Illustrates my point exactly. It just depends what you mean by 'high tensile'. At the strength that I understand the shank to be by design, not Bisplate 80 for the Canadian and Chinese production but ASTM 514A or equivalent, the UTS is 100 ksi (758 Mpa)(44 ton/in.sq) I would expect a shank in that material to bend if I applied sufficient force to it. I doubt if it would have been any different in Bisplate 80. We have been shown several photos of other bent anchors, including Manson and Fortress. I don't find any of them to be surprising.

If things don't bend, they break. This property is determined by the Charpy value. I have seen a spec for Rocna's material that states a minimum of 27 Joules. Waveboy appears to be carrying out Charpys at present and it will be interesting to see the result.
 
Delfin said:
Thanks all for an interesting discussion of metallurgy - I've learned a lot. The different technological balances that have to be maneuvered between strength and flexibility, weight distribution, welding technique and so on seem like a perfect illustration of the concept used in biology of sub-optimal designs. This is where a system appears to be less than perfect, but on balance is as perfect as it can be. An example might be the size of the human brain. Since it would be better for us all to be smarter (some more than others), our brains should be bigger and that would be adaptive. However, if our brains were any bigger, they would literally overheat from the immense blood supply required, so our skull shape would have to change. But change that, and you wouldn't see as many live births. In other words, the sub-optimal design of a smaller brain turns out to be the best design of all.

How this whole discussion affects the average boater regarding something that seems simple, like an anchor, but isn't is the observation that if you can't trust the manufacturer to deal fairly and tell the truth, you can't possibly be expected to sort out all the design issues and make an intelligent choice since you can't get the facts. And if there is one thing I have learned about Rocna so far, is that getting facts from them that are reliable is mission impossible and when you do, many appear to be made up, so how could anyone buy their product?

For an illustration, here is a photo of how the 'high tensile' shank of a Rocna performed under load. I'm not sure if this is a special design made by Rocna for anchoring around corners, or an illustration of why buying from some manufacturers has a great deal more risk to it than buying from others.
Click to expand...
Whatever the steel composition is it must have taken a huge force to bend it.

Perhaps if the anchor was wedged in rock you would expect that. If the seabed was anything else then isn't the picture a fantastic testimony to the holding power of the flukes?
 
SolentBoy said:
Whatever the steel composition is it must have taken a huge force to bend it.

Perhaps if the anchor was wedged in rock you would expect that. If the seabed was anything else then isn't the picture a fantastic testimony to the holding power of the flukes?
Click to expand...
Or the use of mild steel forthe shank?
 
SolentBoy said:
Whatever the steel composition is it must have taken a huge force to bend it.

Perhaps if the anchor was wedged in rock you would expect that. If the seabed was anything else then isn't the picture a fantastic testimony to the holding power of the flukes?
Click to expand...
If the shank can bend like that simply shifting around on the seabed, then they have a bigger problem than I thought.

Setting aside the technical aspects of the metallurgy, I wonder if a purchaser of an anchor with a 'high tensile' shank would expect this to happen? How would the anchor look any different if the shank were made of low grade steel? Again, I think the honesty and integrity of the manufacturer has to be something one can rely on when deciding what kind and design of safety equipment to trust one's boat to.
 
Delfin said:
If the shank can bend like that simply shifting around on the seabed, then they have a bigger problem than I thought.

Setting aside the technical aspects of the metallurgy, I wonder if a purchaser of an anchor with a 'high tensile' shank would expect this to happen? How would the anchor look any different if the shank were made of low grade steel? Again, I think the honesty and integrity of the manufacturer has to be something one can rely on when deciding what kind and design of safety equipment to trust one's boat to.
Click to expand...

So if all the manufacturers of anchors have seen one of their anchors either bend or break under certain extreme conditions, are they all lacking honesty or integrity. Of course not.
Delfin, you certainly do seem to have an axe to grind?? Perhaps you are one of those with intentions that are dishonourable or perhaps you have an ulterior motive other than discovering the truth?
 
Scotty_Twister said:
Perhaps you are one of those with intentions that are dishonourable or perhaps you have an ulterior motive other than discovering the truth?
Click to expand...

I'm curious to know how you have come to the conclusion that there are a number of people with "dishonourable" intentions and ulterior motives.....and I'ld be fascinated to know what those intentions and motives could possibly be.

Perhaps I'm being naive, but I cannot see how Delfins postings indicate anything other than, like many others, he is trying to get some truthful honest answers to several questions.
 
Well perhaps its due to the fact that the slant of your postings and Delfins, seem somewhat biased throughout this thread (and the thread lost to us), to denegrate one manufacturer.
It seems that you don't wish to see any other side to the discusssion other than you own, even when experts give some clear facts.
 
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One of the problems on this, and other fora, is that the anchor outfit 'in question' only answer questions that put them in a good light. Plenty other questions just get ignored. No surprise, but... And the disconnect with CS over years of nasty negative adverts. Hey! we will fix that......Why now and not years ago?
 
DownWest said:
......Why now and not years ago?
Click to expand...

Good question.

From what I have seen CS has been annoying the socks off people for years. It's certainly clear that many of the other manufacturers have been very, very angry with his antics. Even Rocna have said that he is hard to deal with!!! Add to this suppliers, customers and ex employees and you have a cocktail for exactly what is now happening.
The whole thing is then complicated by Rocna's apparent difficulty in saying anything without trying to put a spin on it.

This time, for whatever reason, lots of people have said "enough is enough" and what you see is the result.
 
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