Kenter Shackles — Frequently Asked Questions
Answers to the questions we are asked most often. If yours isn't here, contact us — we answer technical questions whether or not you buy from us.
Sizing and Fit
How do I know what size Kenter I need?
A Kenter is sized by the nominal diameter of the chain it joins — not by the dimensions of the shackle itself. If you don't know your chain size, measure one link and work backwards. For standard stud link chain:
- Link length = 6 × chain diameter
- Link width = 3.6 × chain diameter
So a link measuring 156mm long is 156 ÷ 6 = 26mm diameter — 1" chain. The same link should measure about 94mm wide: 94 ÷ 3.6 = 26mm, which agrees. Measure both and check they agree; if they don't, measure again before ordering.
If you're unsure, send us your measurements and photographs and we'll identify it for you.
My chain is imperial. Do you sell imperial Kenters?
Metric and imperial are the same ladder. 5/8" is 16mm, 1" is 26mm, 1-1/2" is 38mm, 2" is 52mm, 3" is 76mm. Every product on this site lists both. Kenters follow the standard size series, which steps about 1.5mm below 22mm, 2mm from 22mm to 70mm, and about 3mm above that — so the imperial figure is a nominal name for the size, not an exact conversion of it.
What if my chain is slightly worn or between sizes?
Kenters are manufactured to a ±2.5% sizing tolerance, which is why a metric Kenter fits equivalent imperial chain. A 34mm Kenter, for example, measures 33.1–34.8mm in practice. If your chain sits between two nominal sizes, tell us the measurement and we'll advise.
What sizes do you offer?
Our Kenter range runs from 5/8" (16mm) up to 3-9/16" (90mm), in both Lloyd's Register and ABS certification. Proof and breaking loads for every size are in our Size and Load Table. If you need a size outside that range, contact us.
What is the smallest Kenter available?
5/8" (16mm) is the smallest we stock, and the smallest that is regularly asked for. The standard size series does continue below it, but demand is rare and availability varies. If you need something smaller, tell us the chain size and we'll tell you what can be had.
Certification
Which certification do you supply?
We supply Kenters certified by Lloyd's Register (LR) and by the American Bureau of Shipping (ABS). Every unit is individually serialized and the serial number is covered by the certificate supplied with it. Other societies can be sourced to order — contact us with your requirement and quantity.
My specification calls for ABS. Can I use a Lloyd's certificate?
In most cases yes. For insurance and classification purposes, any major society certificate is normally accepted. LR, ABS, DNV and BV are all IACS members working to the same underlying standards — ABS is American, Lloyd's Register and DNV are European. If your contract names a specific society, check with your surveyor or class representative before ordering, and contact us if you need that society specifically.
What other classification societies can you source?
We stock Lloyd's Register and ABS. Any other IACS member society can be sourced to order — contact us with your requirement and quantity.
IACS (the International Association of Classification Societies) sets the common technical standards these societies certify to. Ranked by world fleet tonnage in 2025:
- ABS — American Bureau of Shipping (stocked)
- DNV
- ClassNK (NK) — Nippon Kaiji Kyokai
- Lloyd's Register (LR) (stocked)
- CCS — China Classification Society
- Bureau Veritas (BV)
- KR — Korean Register
- RINA
- IRS — Indian Register of Shipping
- PRS — Polski Rejestr Statków
Ranking: Lloyd's List, 2025.
Is the certificate specific to the shackle I receive?
Yes. Each Kenter is individually serialized and its serial number appears on the certificate. You are not receiving a generic type certificate.
The Product Itself
Is a Kenter shackle the same as a lugless joining shackle?
Yes — the same part under different names. Kenter shackle, Kenter link, lugless joining shackle, chain connecting link and chain connector all describe this component: the joining shackle used to connect two lengths of stud link (also written studlink) anchor chain. "Lugless" is the formal term, and the one you are most likely to see in a specification or a tender document, because the shackle carries no protruding lug or bow. The two interlocking halves it splits into are sometimes called half links. If your specification names any of these, this is the part it means.
What is the difference between a Kenter and a D type joining shackle?
Both join stud link anchor chain, and ISO 1704 covers both, but they are not interchangeable in service.
A Kenter type joining shackle is lugless. It splits into two interlocking halves and, once assembled, sits within the same envelope as a common link — so it passes over the cable lifter (the gypsy or wildcat) and through the hawse pipe without snagging. That is why it is the standard way to join chain shots along the running length of an anchor cable.
A D type joining shackle — also called a dee shackle or end shackle — has a bow standing proud of the chain profile. It will not run over a cable lifter cleanly, so it belongs at terminations: connecting the cable to the anchor, or to a swivel, rather than in the running length.
Both are secured with a taper pin. The Kenter additionally needs a lead plug driven in over the pin head, and is not safe to put into service without one.
What is ISO 1704?
ISO 1704 is the international standard for stud link anchor chains. It specifies the shape, proportions, nominal dimensions and tolerances of the components of an anchor chain — common links, enlarged links, end links, and both Kenter type and D type joining shackles.
It is a dimensional standard, not a weight one: it defines the geometry, and mass follows from that. It is also separate from classification society certification, which covers the material, the manufacture and the testing rather than the shape. A shackle can be built to ISO 1704 proportions and still need an LR or ABS certificate to satisfy a specification — the two answer different questions.
The current edition is ISO 1704:2022. It superseded ISO 1704:2008 and, among other changes, corrected errors in the dimension tables of that edition.
What brand of Kenter shackle is this?
There is no such thing as a Kenter shackle "brand". It is a universal design. All manufacturers produce to the same dimensional and material specifications, and any Kenter of a given size fits any chain of that size. What differentiates one from another is the certificate and the traceability behind it — which is what you are actually buying.
What grade are your Kenters?
Grade 3. Grade 3 is the working standard for anchor and mooring chain, and a Kenter should always match the grade of the chain it joins. Proof and breaking loads follow the IACS standard and are published for every size, in both Grade U2 and Grade U3, in our Size and Load Table.
What is the finish, and will it survive saltwater?
Natural forged steel with a protective varnish, which is the standard finish for anchor and mooring service. Kenters are designed for saltwater use. Inspect for corrosion as part of your normal chain inspection routine.
Do you supply Kenters in other materials?
Our standard Kenters are forged steel to Grade 3, which is what classification societies certify. If you have a special material requirement, contact us and we'll tell you what is realistically available.
Is this for stud link or studless chain?
Our Kenters are for stud link anchor chain, which is the standard for anchoring and mooring. If you are working with studless chain, contact us before ordering.
What Else You Need
Is anything else required to install a Kenter?
Yes — two items, both sold separately:
- Lead plug — required to secure the taper pin once the Kenter is assembled. A Kenter is not safe to put into service without one.
- Drive pin punch — required only for disassembly, to drive the taper pin back out.
What size lead plug do I need, and how many come in a pack?
Lead plugs are supplied in packs of three. If you need 50 plugs, order 17 packs. One plug covers every Kenter size up to 3" (76mm) — for smaller Kenters, simply cut off the excess with a saw or pliers before hammering it flush.
If you need a plug for a large Kenter, or a specific plug dimension, contact us with your Kenter size and we'll confirm what fits and what we have available.
Which punch do I need?
The punch must suit the taper pin of your Kenter size. The punch listed on this site is sized for 5/8" Kenters — for any larger size, contact us with your Kenter diameter and we will quote the correct punch.
Can I buy a replacement taper pin?
Taper pins are replaceable if damaged or lost, but on Kenters below 1" the cost of a replacement pin approaches the cost of a new Kenter, so it is rarely worth doing. Contact us with your exact size for pricing.
Ordering, Stock and Delivery
Do you have my size in stock?
Stock varies by size and by certification. If your size isn't shown as available, contact us — we source Kenters regularly and can quote lead time for any size.
Is there a discount for quantity?
Yes. Prices shown are for single units. Contact us with your quantity and we'll revise the pricing.
What is the lead time?
In-stock items ship from our Montreal warehouse, often the same day if ordered early enough. For sizes we source to order, contact us and we'll confirm the current lead time before you commit.
Can you ship to the USA, the UK, or my country?
Yes. We ship worldwide. Everything leaves our warehouse in Montreal, Canada, and we regularly supply customers across the United States, the United Kingdom and Europe, the Middle East, Asia, Africa, Australia and the Caribbean. If you are somewhere we have not shipped before, ask — the answer is almost always yes. There are a small number of destinations we cannot serve; these are listed below.
For urgent requirements contact us directly; we can often ship the same day on in-stock items. Note that on anything leaving Canada you are the importer of record — see our shipping policy.
Do you ship to Nigeria?
No. We do not ship to Nigeria and we do not quote Nigerian enquiries.
Please do not email us for a quotation. We cannot provide a price, a lead time or a shipping cost for delivery to Nigeria, and we do not respond to requests for them.
Who pays duties and taxes?
You do. On any shipment leaving Canada you are the importer of record — not Dibblee Industries. The customs entry is filed in your name, and every import duty, tariff, customs fee, brokerage charge and destination tax is yours to pay.
Our prices are for the goods alone. They do not include any of the above, and nothing is collected at checkout on your behalf. Whatever your broker or the carrier bills you on arrival is separate from what you paid us.
Tariff rates have been changing frequently, so confirm the current position with your customs broker before you order. We will supply the commercial invoice, the HS code and the country of origin for your entry — but we cannot quote your landed cost, and we are not able to act as importer on your behalf.
What if I have trouble ordering on the site?
Contact us and we will process your order manually. This is common for international and large-quantity orders, and we are happy to do it — please don't abandon an order because the website is giving you difficulty.
Use and Safety
Can I use a Kenter shackle for lifting?
No. Kenter shackles are not approved for overhead lifting and are not intended to bear load in air. They are for joining anchor chain and for mooring service only. Using one as a lifting component is unsafe and outside its certification.
How do I install one?
Installation requires qualified personnel, a drift punch and a sledgehammer sized to the chain. In brief: disassemble the Kenter, insert the taper pin through the chain link and Kenter body, drive it fully home large end first, then secure it with a lead plug hammered flush so the pin cannot back out. Inspect before placing into service. Full instructions appear on each product page.
Can a used Kenter be re-certified?
No. A used Kenter should be replaced rather than re-certified. Kenters are a consumable part of a chain system.
How often should I inspect?
Inspect before each use and as part of your regular chain inspection. Look for deformation, cracking, corrosion and a missing or loose lead plug. Replace the Kenter if you find dimensional change or cracking.
Anchors
What size anchor do I need for my chain?
Anchor mass and chain diameter are both set by your vessel's equipment number in the IACS tables, so the two go together. As examples: 26mm chain pairs with an 855 kg high holding power bower anchor, 38mm with 1,845 kg, and 48mm with 2,835 kg. Our Anchor and Chain Sizing Guide gives the full table from 20.5mm to 48mm, along with the chain length specified for each size.
What is a high holding power (HHP) anchor?
High holding power is an approval category, not a brand or a shape. A classification society type-approves a design as HHP when it demonstrates approximately twice the holding of a standard stockless anchor of the same mass. Because of that, the equipment tables allow an HHP anchor to be roughly 25% lighter than the stockless anchor it replaces — for 38mm chain, 1,845 kg instead of 2,460 kg. Lighter anchor, same holding, less strain on the windlass and lower freight.
Is HHP the same as an AC-14?
No, though the terms are often used interchangeably. HHP is the approval category; AC-14 is one particular design within it — the most widely specified HHP stockless anchor, and the one most people mean when they say HHP. Other type-approved HHP designs include Spek, Pool N and Flipper Delta. There is also a higher category, super high holding power (SHHP), which includes designs such as Pool TW.
Which HHP design should I choose?
Unless your specification says otherwise, the AC-14 is the default and the one we normally quote. It is by far the most widely specified HHP stockless anchor, it holds very well in sand and mud, and it is what most merchant vessels are built to carry.
Other designs suit particular conditions. Flipper Delta and N-type anchors perform across a wider range of seabeds and are common on large vessels and offshore work. Where a specification calls for super high holding power, types such as Pool TW apply. Tell us your vessel, your chain size and where you anchor, and we will advise.
Do you supply anchors?
Yes. We quote the AC-14 as standard, in the mass matched to your chain size, certified to ABS or Lloyd's Register.
We are not tied to a single type, though. If your specification names something else — Spek, Pool N, Flipper Delta, or an SHHP design such as Pool TW — we will source it. As with Kenter shackles, what matters is the specification and the certificate, not a brand.
Send us your chain size, your vessel's equipment number, or simply the anchor type named in your specification, and we will quote it.
Mooring Chain and Grades
What is ORQ chain?
ORQ stands for "Oil Rig Quality" — the older name for offshore mooring chain, from before IACS formalised the R grades in UR W22. It has not been a current designation for many years, but it is still written on rig inventories, old certificates and specifications that were copied from the last job. In the modern range it sits at the bottom, broadly where R3 is now. If your paperwork says ORQ, send it to us and we will tell you the modern equivalent before you commit — see ORQ and oversize mooring chain.
What is the difference between anchor chain grades and mooring chain grades?
They are different families and they do not overlap. Anchor chain cable is Grade 1, 2 or 3 — often written U1, U2, U3 — to IACS UR A1 and W18. Offshore mooring chain is R3, R3S, R4, R4S or R5 to IACS UR W22, for floating production units, offshore loading systems and similar. A ship at anchor uses the first; a moored floating structure uses the second.
Can I use a Grade 3 Kenter shackle on mooring chain?
No. W22 does cover Kenter shackles for mooring, with their own machining requirement — the fillet radius must be at least 3 percent of nominal diameter — but they are made to the R grade, from a forge separately approved by the Classification Society for that purpose.
W22 §1.2.3 is explicit that each grade is approved individually and that approval for a higher grade does not constitute approval of a lower one. A Grade 3 Kenter made for anchor chain is not an R4 mooring Kenter, whatever the diameter says. If you are replacing a connector in a mooring, check which family it belongs to before ordering.
Is R5 the highest grade, or is there something above it?
In IACS UR W22 Rev.6, the revision we work from, R5 is the top — §1.2.1 names five grades and stops there. Above R4 the specifications are already partly proprietary: §1.2.2 allows manufacturers' own specifications for R4S and R5 subject to design conditions and class acceptance.
R6 does exist commercially, developed for deep water and floating wind, and appears in standards work outside the revision we hold. It is not something to assume on a drawing. If a specification calls for R6, tell us and we will confirm what a mill can actually certify against before quoting.
Do you supply mooring chain larger than 90 mm?
Yes, to order. Our listed sizes stop at 90 mm because that is where the rest of our range tops out, so every listed chain size has a joining shackle to pair with it. W22's own dimensional tolerances run to 222 mm and the load formulas hold the whole way, so a larger diameter is a quoting question rather than a technical one — and because the loads are calculated rather than looked up, we can give you exact proof and break figures for any diameter before the enquiry goes anywhere.
Where do the mooring chain load figures on your pages come from?
They are calculated from the formulas in IACS UR W22, not transcribed from a table — W22 does not publish a load table. Proof and break loads are a coefficient times d² times (44 − 0.08d), in kN, with d the nominal diameter in millimetres. Stud link weight is 0.0219 d² kg/m and the five link pitch runs 22d to 22.55d. The coefficients are printed on each grade's page so you can check our arithmetic.
Lifting Chain Grades and Markings
What does the "-8" mean on a chain fitting, like 6-8 or 22-8?
It is the grade, not a part number. Fittings for lifting chain are marked size first, grade second. So 6-8 is a fitting for 6 mm chain in Grade 8, and 22-8 is the same thing for 22 mm chain. A marking like 18/20-8 means one fitting covering both 18 mm and 20 mm chain, still Grade 8.
The number in front is the chain diameter in millimetres. The number after the dash is the grade of the steel. Once you know that, the whole marking reads at a glance — see the chain grades guide.
What does 7/8-10 mean on a connecting link?
It fits both 7 mm and 8 mm chain, and it is Grade 10 — which is the same thing as Grade 100.
This one confuses people because it looks like a fraction. It is not. In North American sizing, 1/4" alloy chain is 7 mm nominal and 5/16" is 8 mm, so a single link covers both trade sizes and the maker marks it for both. That is why a link marked 7/8-10 turns up on 1/4" chain.
Is G-100 a standard, or a Chinese brand?
A standard. G-100 means Grade 100, and it is no more a brand than Grade 80 is.
The grade is the nominal breaking stress of the steel in newtons per square millimetre, divided by ten — Grade 100 steel reaches 1 000 N/mm², Grade 80 reaches 800. Europe writes the same grades as 10 and 8, North America as 100 and 80. Two conventions, one steel. A Grade 100 fitting carries about 25% more load than Grade 80 of the same size.
One caution, because it costs people money: a grade forged into a fitting tells you what the maker intended. A test certificate tells you the fitting in your hand was made and proved to the standard by a maker you can trace. Uncertified imports are stamped with grades all the time.
Is a chain connector the same as a Kenter shackle?
No — two different parts that unfortunately share a name. If a search for "chain connector" brought you here, this is the question you want.
A Kenter shackle (lugless joining shackle) joins stud link anchor chain. It is a marine part, built to ISO 1704 proportions, certified by a classification society, and it is sized to pass over a cable lifter.
A Grade 80 or Grade 100 chain connector joins short link lifting chain. It is an industrial part covered by EN 1677-4 and ASTM A952, marked with a size and a grade as above, and it has nothing to do with anchor chain.
They are not interchangeable in either direction. If you need the marine part, see our Kenter shackles; if you need the industrial one, see the Grade 80 and Grade 100 chain connectors.
Can I use your chain connectors for overhead lifting?
No. They are a hardware item. They carry no test certificates, and we do not sell them for overhead lifting, for marine certified service, or for anything supporting a person.
A grade forged into a fitting tells you what the maker intended. It is not a certificate, and we do not claim one for these.
Still Have a Question?
We are happy to answer technical questions — sizing, certification, compatibility — whether or not you end up ordering from us. Send us your measurements, photographs or specification and we'll tell you what you need.
Dibblee Industries Ltd. / Les Industries Dibblee Ltée, Montreal, Quebec.