NOTE - the following is written in a non-technical manner to make is easier to understand by all. There is more to some parts of it and there are varying Regulations and Specification depending on just where in the world you are. The below is written genericly and is not to be used randomly without checking local Laws, Regulations or Specification requirements. You may just end up getting yourself in the pooh or hurt. Also some of the terms are 'as used in the industry' as opposed to the strict technical meaning of them.

There are some regional variations on both the terms and what they apply too but the below are generally the most commonly found world wide.

- The numbers used in our website relate to the chains we have. It is not a good idea to use our numbers when looking at other manufacturers chains, especially with some products made in Eastern countries. In many cases they will be the same but in some cases they will not be. It is very important from a safety aspect to ensure you get the numbers from the manufacturer that made the chain. Using any number in a generic fashion may unintentionally leave you in a very dangerous place.

Chain Terminology

Wire Size

The size of the wire used to create a link. This is the size the chain is called so if you measure the wire size at 8mm, for example, that means the chain you have will be called a 8mm.


This is the measurement of a link length measured internally. While that isn't the strict definition of the term the measurement is effectively the same. Often you will see something like 'P=30' in some chain talk. That is a shortcut way of saying the Pitch is 30mm.


This is the width of a link and is measured externally. Be aware that how a link width measuremnt is reported does vary a fair bit world wide. It is often see as the internal measurement. We always use the external one though as it is a bit more common.

Chain measurements


This is the Standard the chain must be built to meet or exceed to be called and comply with any specific Standard. These Standards are administered by the International Standards Organisation (ISO). Note: Most countries comply fully with these Standards but some just use the name even if their product doesn't meet specification.


This is the Grade the chain meets, which relates to the raw metal quality, strength and finishing processes. The Grade denotes the strength rather than any physical measurements of a link. Most reputable manufacturers build to a Grade L (30) or in some cases Grade M (40) and in the very odd case higher. Many of the chains coming out of the East are only Grade 20 or in other words only ½ the strength of a Grade M (40). Until the relitively recent arrival of these very low grade eastern made chains the norm was Grade L (30). When looking at anchor chains a low grade is 20 (generally most of those all come from the Eastern countries), the most common and has been for a long while is 30, becoming quite common is 40, hard to get but there is some 50 and the strongest available that is galvanised is a Grade 70. The letter you may see being used is the new way of denoting a Grade but as it is not in universal worldwide use as yet you'll often see things like L (30), Grade L being the new designation for a Grade 30. As a rough ball park number you can work on a 25% increase in strength for every increase of 10 to the Grade number. So a Grade 40 is roughly 25% stronger than a Grade 30.

Working Load (WLL)

This is the load that the manufacturer recommends you never exceeed. This is to allow for wear and tear over the years you'll be using it. WLL is usually 25% of the chains Break Load, but there are 1 or 2 chains that use diffeent margins, the US G40HT being the main one. Exceeding WLL can be dangerous. WLL is usually referred to in Kilos (or maybe pounds for those using the old school measurement system). Read this description togeather with 'Design margin', below, for a better understanding of it all.

Proof Force

This is also called Proof Load. This is the load the chain was loaded to in the factory during the testing procedure. Proof Load is normally 50% of the chains Break Load and is usually referred to in KiloNewtons.

Break Force

This is the load at which the chain will fail. It is found from representive testing. It is quite possible the chain will exceed that number but by how much no one knows so don't try to find out, that would be dangerous and stupid. This load is usually referred to in KiloNewtons.

Design Margin

This is a sort of 'Safety factor' that is built in to the load numbers to allow for wear and tear over the years a chain is in use.The industry standard Design Margin is usually 4:1, meaning the break load of a chain is 4 times it's Working Load Limit. But there are a few, a small few, that have other Design Margins. In our website all Design Margins on chains are 4:1 unless stated otherwise.


What the protection layer/s are usually called i.e Hot Dip Galvanised, Zinc plated, Nickle plated and there are many more.


This is a more technical explaination of just what the Finish is.


The degree of calibration. Less tolerance means a higher level of calibration.


This basically means has the chain been 'stress releived' to take out the stress and strains created during the manufacture and welding processes. Chains that haven't been Normalised tend to behave badly after a while, especially under good loads. As Normalising is energy hungrey is it often a process left out by manufacfurers of cheap chains in order to save cost.


MarkingsWhat stamps, if any, are on the chain. The requirements for this vary depending on the Standard and local requirements. Often chains under 8mm don't have them. Some manufacturers use the standard 1 stamp per meter or 22 links, whichever is the shortest distance but some stamp every link. NOTE: Having a stamp is NO assurance the chain is good or even what the stamp says it is. Give us 3 months and we could have chain with your name stamped on each link, it will come from an eastern country as reputable manufacturers will not do that.

Maximum Length

This is the longest length of this sized chain we tend to carry as a stock item. We can join lengths and/or can get far far longer lengths in one piece if you require it.

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