OK so you have got a great anchor now, and now you need to connect it to your chain.
There is little logic in buying a quality anchor unless you attach it to the chain with a good quality shackle, better from a reputable manufacturer.
The shackle you use should be a ‘Bow’ shackle with the bow through the slot in the anchor shank and the pin through the chain link.
There are 3 qualities of shackles. Unbranded shackles that you can source easily and cheaply from a hardware store anywhere in the world. These are great shackles for everyday use or if you need to secure your dog but are a complete liability on a yacht. They may not have been tested, you have no idea of the quality. They look like a ‘good’ shackle - because all shackles are made to the same or similar dimensions. We don’t recommend that you have them on your yacht - they are too easily mistaken on a dark night in the rain for a good quality shackle.
There is a subsection of these cheap shackles and they will have China embossed on the body of the shackle. Don’t be deceived there are hundreds of shackle makers in China - these ‘China’ branded shackles might be ‘all right’ but again - they might be a load of rubbish. There might be nothing wrong with the ones you see - there are excellent Chinese manufacturers - but if the manufacturer does not have the pride to add their specific brand or company name - walk on by.
The other 2 categories of shackles are commonly called rated shackles. These shackles have the Working Load Limit (WLL) embossed on the body, they usually have the manufacturer’s name, or a unique brand name, they sometimes have a simple coding, say 2 letters - a batch mark, they have the size, commonly in Imperial units and sometimes the country of manufacture. The 2 categories are identical - except the WLL for the same size will be different.
If we take a 3/8th” shackle, this is the size that will fit a 5/16th” or 8mm chain, then one group of shackles will have a WLL of 1t and the other a WLL of 2t - note for the exact same size of the shackle. So a 3/8yh” shackle might be marked WLL 2t or more commonly 1t. The 1t x 3/8th” shackle is classified as a Grade A shackle and the 2t x 3/8th” shackle is classified as a Grade B shackle. Some manufacturers fudge the specifications in Europe and sell 2t x 3/8th” shackles omitting to mention that the 2t is 2 short tons, 4,000lbs which is a far cry from 2 metric tons, 4,409lbs. The difference in strength is not a big issue - the morality of misleading customers does raise questions.
Now - a 3/8th” shackle with a 1t WLL used in an 8mm chain looks ‘safe’. 8mm G30 chain has a WLL of 750kg and MBS, minimum break strength, of 3t (vs an MBS of 6t for the shackle). If you read the small print on shackle maker's websites they will say (if they are a quality supplier) that if the shackle is loaded at 45 degrees or 90 degrees the WLL should be reduced by 25% or 50%. Suddenly the WLL of that 3/8th” shackle could be 500kg - much less than the WLL of the chain. For this reason, we do not recommend Grade A shackles. The chance of a shackle ‘locking up’ in the slot in the anchor shank is not great but it does happen (it has happened to us, and probably to many more), and buying Grade B shackles is a ‘cheap fix’.
Our recommendation for shackles is simple and no, we do not have any business relationship with the following companies, they just proved to be good.:
Buy either Crosby G209 A shackles, part of their Platinum Range (with silver pins) or Campbell Orange Pin shackles or Peerless G80 shackles. All of these shackles are Grade B shackles and for a 3/8th” shackle has a WLL of 2t.
Or see page 83 of the Campbell chain catalog
Crosby is a well-known manufacturer of lifting components and recently acquired Gunnebo of Sweden. Campbell manufacture chain and lifting components and are part of the Apex Tool Group. Crosby have a worldwide distribution network but Campbell tends to be more focussed at the local US market - but make a Google check for both.
Sadly these shackles are made in 3/8th” sizes as the smallest. For smaller sizes, we recommend buying from Peerless, America’s largest chain maker - now part of Kito. Again search google for distributors. Kito does have a distribution center in Germany - they may also stock Peerless shackles.
The Peerless range of Grade B shackles are their Blue Pin products in their G80 range, also called Peerlift shackles.
The smallest shackle they make is a 3/16th” with a 500kg WLL.
We admit sourcing any of these shackles demands some stamina and when you buy - buy 2. You will not need to replace them very often, 5 years - but you may drop one overboard!
Do not forget to secure the pin! We have found Loctite perfectly acceptable for securing the cotter pin, we recommend securing with Loctite and mousing wire - belt and braces does no-one any harm!
There are other reliable manufacturers of shackles- Van Beest in Holland and Yoke in Taiwan are 2. However neither make a grade B shackle of a size small enough for a Viking anchor and we have not tested their Grade A shackles. If you find shackles of the 3/8th” size purporting to have a 2t WLL - check the website, if the 2t refers to imperial short tons - wonder about the ethics of selling a shackle specified in short tons in a region using metric measures.
We do not recommend the use of stainless shackles in the rode. 316 stainless shackles, of a 3/8th” size, can have a MBS of near the same as a Grade A shackle, say 5t or 6t. However, they deform under much less tension than a steel shackle and if stressed they may deform and you may not be able to undo the pin. This will demand the use of a hack saw bolt cropper or angle grinder - none of which is very convenient and sometimes not safe. Additionally stainless can cause premature corrosion in the chain, or anchor. Make the effort to buy a good Grade B shackle from Crosby, Campbell, or Peerless.
You will find that after a few years of use the first few links, those attached to the shackle, are preferentially corroded - you will see signs of rust. This is common, you have a mild steel chain in contact with an alloy shackle and close to an alloy steel shank. Just cut those first few links off - and replace the shackle and attach to the anchor (or use the spare shackle you bought all those years ago!)
Our recommendation for choosing a shackle is to take the anchor and 3 links of your chain to the chandler - and try the shackle for fit. If you are going to ‘mail-order’ to source your shackles - do as we suggest and try your anchor and chain with ‘off the shelf’ shackles. Shackles are made to a standard size, there are slight variations, but if you size with most shackles you are fairly sure that if the one you try fits then the one you order will also fit. A bad fit is a shackle that can ‘stick’ in the slot. To reassure you - we have designed the slot in our anchor shanks to be compatible with the shackle size we think most appropriate.