Anchor chain info

[ANDY_W]

Can any kind soul tell me the weight per metre and the breaking strain of 6mm and 8mm anchor chain?

I am planning an anchor locker and need the info to work out how much I can carry and the effect on the boats' trim.

Thanks, Andy.

 

[Moggy]

According to Marinestore Chandlers, their 6mm chain is rated at 1.8 M/Tonnes and their 8mm at 3.1 M/Tonnes. I think it would be difficult to generalise...the breaking strain would depend on the quality of the steel it's made from...buy British!

 

[Elza_Skip]

Try here for information on chain

http://www.jimmygreen.co.uk/tech_pages.asp?article_id=1

 

[Elza_Skip]

This is a better one...

http://www.jimmygreen.co.uk/tech_pages.asp?article_id=10

 

[Kylora]

The May 2006 issue of Yachting Monthly, Page 86, has a article where they carried out destructive testing on various anchor connectors.

They found that 8mm galvanised chain, with a nominal breaking load of 3.2 tonnes broke at 4.4 and 4.9 tonnes, whilst the stainless steel broke at 4.25 t.

http://www.yachtingmonthly.com/auto/ym/inprint/20060313100052yminprint.html

 

[Rick]

Far as weight goes, here in Aus, our short link local chain is sold by weight - 6mm is 54m and 8mm is 34m for 50kgs each.

 

[GMac]

6mm - 0.8 kg/mt - Break Load 1630kg - SWL 400kg
7mm - 1.0 kg/mt - Break Load 2550kg - SWL 630kg
8mm - 1.4 kg/mt - Break Load 3200kg - SWL 800kg

That is well made Grade 30, all grades actually weight wise, strengths obviously will differ. This applies to all short link chain made by a reputable manufacturer. There will be a tiny differance between some standards but negligable. Actual break loads will be above those to some amount but don't take that in to you calulations, you don't know how much 'some' is.

Buy Chinese made and you will get TOLD the same numbers but put it to the test and it is very very unlikely you will actually get them. We have yet to find a chinese made that does the numbers they say it will.

 

[GMac]

[ QUOTE ]
The May 2006 issue of Yachting Monthly, Page 86, has a article where they carried out destructive testing on various anchor connectors.

They found that 8mm galvanised chain, with a nominal breaking load of 3.2 tonnes broke at 4.4 and 4.9 tonnes, whilst the stainless steel broke at 4.25 t.

http://www.yachtingmonthly.com/auto/ym/inprint/20060313100052yminprint.html

[/ QUOTE ]

Those numbers would vary from manufacturer to manufacturer and should not be relied on the be there in all cases.

 

[Salty John]

6mm is 0.8 kg per meter, 8mm is 1.4 kg per meter. That's for short link grade 30 and 40 which I assume you are using. Long link is slightly lighter.

 

[ANDY_W]

Very many thanks to all who replied. As usual, the response was prompt and informative!

Andy.

 

[VictorII]

Can somebody explain why the Chinese chain is poorer quality? It would seem that the construction of chain is something even the Chinese would know how to do. They probably invented it 3000 years ago!

Is it quality control, poor knowledge,....?

 

[craigsmith]

[ QUOTE ]
Can somebody explain why the Chinese chain is poorer quality? It would seem that the construction of chain is something even the Chinese would know how to do. They probably invented it 3000 years ago!

Is it quality control, poor knowledge,....?

[/ QUOTE ]Just ethics /forums/images/graemlins/grin.gif

A bit of chain history: http://www.nvo.com/baldtus/historyoftheanchor/
Bit of promotional fluff but the history older than 100 years is interesting.

 

[GMac]

[ QUOTE ]
Can somebody explain why the Chinese chain is poorer quality? It would seem that the construction of chain is something even the Chinese would know how to do. They probably invented it 3000 years ago!

Is it quality control, poor knowledge,....?

[/ QUOTE ]

Built to a price which is sweet F word all.
Poor machinery, if any. Much is still made by hand.
Lack of knowledge.
Huge users of recycled metals i.e chain comprises of 2 parts steel (of unknown quality) and 1 part Toyota dashboard.
Lack of understanding end use.
Lack of quality control.
The Art of War, a good read.

A mix of all of those is my understanding.

 

[vyv_cox]

A very superior attitude! Why do you assume that anything made in China is inferior? Truth is that 90% of consumer goods seem to be made there and they are the usual blend of good and bad. I have recently bought a new laptop that is clearly labelled Made in China and it is perfectly acceptable in function and appearance.

I am old enough to remember when Japanese goods were labelled as inferior by smart British folk. How are the mighty fallen!

As the author of the YM chain and links article I can tell you that many of the items made in China outperformed those made in the enlightened west.

 

[GMac]

[ QUOTE ]
A very superior attitude! Why do you assume that anything made in China is inferior? Truth is that 90% of consumer goods seem to be made there and they are the usual blend of good and bad. I have recently bought a new laptop that is clearly labelled Made in China and it is perfectly acceptable in function and appearance.

I am old enough to remember when Japanese goods were labelled as inferior by smart British folk. How are the mighty fallen!

As the author of the YM chain and links article I can tell you that many of the items made in China outperformed those made in the enlightened west.

[/ QUOTE ]

Oh calm down and take a gentle breath.

We were not talking 'anything', we were talking anchor chain i.e 1 thing only.

Who hasn't got a house full of Chinese made somethings. Totaly agree that there is good and bad. There is getting to be a lot more good than bad.

Chinese made anchor chain will become good one day, at the moment 95% of it is bad.