Every sailing or motor yacht that ventures from their home berth will be sure to need an anchoring system that they can rely on in adverse weather at some point.
Calibrated anchor chain forms an integral part of that system. An anchor rode can vary between:
It stands to reason that the strength and the durability of the chain will be extremely important for yachts that rely heavily on their anchoring system on an extended cruise, and especially those equipped with all chain and combination rodes with a substantial proportion of chain.
Calibration is extremely important to the successful and reliable operation of your windlass - there is more information below, and also in these two articles:
Jimmy Green Marine offer a choice of 3 different top quality manufacturers for Hot Dip Galvanised Calibrated Grade 40 Anchor Chain, an option for hot dip galvanised high strength Grade 70 hot dip galvanised chain and a choice of Grade 3, Grade 6 and Grade 6+ stainless steel anchor chain
Sourced exclusively from Lofrans, renowned worldwide for their range of top quality windlasses. Lofrans manufacturing is based in Monza, Italy. Lofrans have been producing top quality windlasses for over 50 years and now they have the chain to match. Lofrans Grade 40 chain is clearly stamped LFR at regular intervals as testimony to their belief in the quality of their chain.
Titan™ Marine is a brand of Canada Metal (Pacific) specialising in World Class Marine Anchor Chain. Titan Grade 40 Calibrated, hot dipped galvanised Anchor Chain is engineered and proof-tested by CMP to specifications exceeding industry standards. Titan specification and break loads are testimony to the quality of the steel and the manufacturing process. All Titan Grade 40 Chain is clearly embossed at regular intervals with G43, CMP and DIN766 or ISO4565 as appropriate as a clear testament to their confidence in the chain and galvanising quality.
Sourced exclusively and directly from MF Catenificio Frigerio, a modern chain manufacturing plant in Italy. MF Catenificio manufacture, hot dip galvanise and proof test their MF40/MF70 chain in their cutting edge, research, test and production facility. The state of the art MF factory is located in Olginate, near Lecco, Lake Como, Italy. The proof load testing process ensures that each individual weld has been completed successfully. MF Calibrated Anchor Chain from 6mm-14mm features enhanced Solid Zinc Galvanising treatment with greater micron depth and longer lasting corrosion resistance.
Sourced exclusively and directly from MF Catenificio Frigerio, a modern chain manufacturing plant in Italy. MF Catenificio manufacture, hot dip galvanise and proof test their MF40/MF70 chain in their cutting edge, research, test and production facility. The state of the art MF factory is located in Olginate, near Lecco, Lake Como, Italy. The proof load testing process ensures that each individual weld has been completed successfully. MF DAMS Grade 70 Calibrated Anchor Chain is available from 8mm-12mm featuring enhanced Solid Zinc Galvanising treatment with greater micron depth and longer lasting corrosion resistance
Hot Dip Galvanising is the process of safeguarding the chain from corrosive elements by immersion in molten zinc at a temperature of around 450 °C (842 °F). The zinc chemically reacts with the steel to form a metallurgically bonded protective coating which is infused into the steel i.e. it is not just a surface finish that can flake off. The process of galvanising anchor chain presents some problems due to the number of moveable parts (chain links) and the weight involved. All our chain deliveries are manually checked for any sign of defective galvanising. Galvanising treatment is measured in microns and is typically 80-100 microns on good quality anchor chain.
Provenance is extremely important for your peace of mind when it comes to your anchor chain because although a careful scrutiny of the galvanising will reveal any rust stains or defects, it is well nigh impossible to check the steel specification without a metallurgist report. Hallmarking will at least confirm the manufacturer and certification will state the grade of steel and the rated break load.
Ketten Walder have been producing the highest quality marine grade 60 chains for 60 years. The attention to detail, stringent testing and checking processes ensure that every chain meets the highest standard.
Available in two specifications: G6 AISI 316L and G6 PLUS AISI 318LN Bright polished finish is standard. G6 Plus comes with a manufacturer 2 year corrosion free warranty as standard. The guarantee can be extended to 3 years with an extra electro-polish process which smooths out micro imperfections and removes ferritic ions to prevent corrosion and staining.
Every length of chain is quality checked and labelled with the manufacturer, the date received and a corresponding batch number when it arrives at Jimmy Green Marine
The batch number is then recorded at the point of sale.
Every chain order is therefore traceable and accountable to the manufacturer Test Certificate.
A copy of the Manufacturer Test Certificate corresponding precisely to the manufactured length from which your chain has been cut is available with your order on request.
Our Delivery charge is based on the total weight and the delivery destination Zip Code.
Lengths of chain under 50kg will generally be packed in a polypropylene sack (sometimes doubled for security)
Lengths of Chain over 50kg will generally be packed on a pallet.
The Freight cost is calculated in the basket and assumes a UK Mainland delivery address until you are signed in with your registered delivery zip code
You are welcome to collect from our Chandlery Store to save this cost.
Calibrated chain is absolutely essential if you have a windlass fitted on your yacht or if you are considering a windlass in the near future.
Calibrated means that each link is manufactured to the same dimensions within a given tolerance.
Windlass gypsys are generally designed and manufactured so that they are compatible with a given size and calibration of chain.
When the dimensions are close but not correct then it is difficult to detect without a practical trial. The problem then normally occurs after a short length has been through the gypsy under load. The difference in size between the chain link and the pocket on the gypsy eventually leads to a jam or a jump.
There is a lot of information available on the internet regarding the calibration of windlasses. This information may come from the manufacturer or even from a fellow yachtsman. This is a very good guide and could well be accurate. However there are some ‘caveats’ which need to be taken into account e.g. Windlasses are normally offered with a choice of different chain sizes and calibrations Any markings or stamps on the gypsy itself may help in this respect. Windlass manufacturers change their specifications over the years and the details of those changes are not necessarily available without a lot of research. If you are not 100% sure of the provenance of your yacht, windlass or gypsy then it is possible that the gypsy has been replaced at some time. The replacement could be a different calibration.
There are only two main calibrations for chain manufactured in Europe: DIN766 and ISO4565
The good news is that the dimensions for 6mm, 7mm, 8mm and 12mm are identical.
10mm is more difficult because the dimensions are different for DIN766 and ISO4565
Both 10mm calibrations are very commonly used in Europe.
Be aware that selecting the wrong calibration, particularly in 10mm, on the vast majority of windlasses will result in ‘jamming’ or ‘jumping’ under load.
Please note that US Calibrations are entirely different to European DIN766 or ISO.
US Chain Descriptions can be confusing because American chandlers tend to cite Working Load Limits rather than Break Loads and they don't normally refer to the grade of the chain as we do in Europe. Be careful with Working Loads because the Break Load will depend entirely on what safety factor the manufacturer is using. The Break Load is self explanatory as is the Grade (30, 40 or 70) The term HT is quite commonly used in the USA but confusingly can refer to two entirely different things. HT meaning High Test which refers to Grade 40 or Grade 43 or HT meaning High Tensile which refers to a higher grade, commonly Grade 70
For information on how Jimmy Green Marine can help you select the right chain for your windlass, please go to Calibrated Anchor Chain - Determining the correct calibration
Calibrated Anchor Chain for yachting and boating is generally manufactured in Grade 30, Grade 40 (also sometimes known as/available as Grade 43 High Test) and Grade 70
Grade 30 is adequate for mooring and anchoring but Grade 40 is 25%+ stronger and a minimum requirement for any serious minded cruising skipper. The weight does not increase with the grade which affords weight saving opportunities for the long lengths required for long distance cruising.
Typical Break Load comparisons e.g. 8mm: Grade 30 = 3200kg ~~~ Grade 40 = 4100kg up to 4400kg according to the manufacturer ~~~ Grade 70 = 70kN = approx. 7100kg 10mm: Grade 30 = 5000kg ~~~ Grade 40 = 6400kg up to 7200kg according to the manufacturer ~~~ Grade 70 = 110KN = approx. 11200kg
There are 3 Different Methods of recording Manufacturer Load Limits
Grade 70 chain is produced from Grade 40 steel by means of a specially designed heat treatment process which results in a break load inexcess of the Grade 70 standard. A specially amended and carefully supervised process for the intitial hot dip galvanising treatment is also required to ensure that the subsequent strength loss is minimalised and the finished product satisfies the appropriate standard. There is no evidence to suggest that re-galvanising has any detrimental effect on the strength of anchor chain, not even Grade 70 if it is carried out professionally because the heating effect is not cumulative.
It is not a myth that Grade 30 chain is very slightly more ductile than Grade 40 and Grade 70 chain. This means that it may distort very slightly more just before breaking. However, the relative difference in brittleness should not be a concern. Once you have subjected your anchor chain to anything like the break load limit, the brittleness effect on the capacity of the chain to survive the extreme forces involved will be minimal. This applies to any of the different grades: 30, 40 , 43, 70. The higher the grade of chain, the tougher it is. Tougher means more resilient to higher loading and more resistant to damage from e.g. impact or abrasion. By far the most important aspect of deploying an anchor chain in severe conditions is to avoid shock loading at all costs. Evidently, the higher the grade that you select for your anchor chain, the less likely you are to overload it.
Higher Grade = Higher Break Load = Less chance of Overloading
The best methods of protecting your chain from having to cope with a snatch load: