ANCHORING GUIDE · IDENTIFICATION TOOL
Chain Selection Guide: Size & Standard Check
Muir’s chain selection guide takes the guesswork out of identifying unknown anchor chain. Measure a few links, enter the dimensions below, and the tool compares them against certified short link chain standards — including DIN766 and ISO4565 — to return your two closest matches. Once you know your standard, you can confirm gypsy compatibility and order replacement chain with confidence.
WHAT YOU'LL NEED
- Vernier calipers — digital or dial, either works.
- A clean, unworn section of chain, three links or more.
- Two of the four link dimensions: width, length, pitch or wire diameter.
STEP BY STEP
How to Use This Chain Selection Guide
Four steps, two minutes — that's all the chain selection guide needs. Measure first, match second, confirm compatibility before you order.
1
Measure your chain
With vernier calipers, measure at least two of the four dimensions shown in the diagram: width (A), length (B), pitch (C) and wire diameter (D). Wire diameter matters most — it sets the nominal chain size.
2
Choose your unit
Enter values in millimetres, fractional inches or decimal inches — the matcher converts and compares them for you.
3
Find your matches
The tool returns the two closest certified standards from our database, ranked by Distance Score — the lower the score, the closer the match.
4
Confirm compatibility
Cross-check the matched standard against your windlass gypsy designation before ordering replacement chain.
Chain Standard Matcher
Reference the diagram below and enter at least two dimensions to find the closest match.
READING THE OUTPUT
Understanding Your Match Results
Each result from the chain selection guide shows the chain standard, nominal size and a Distance Score. A low score means your measurements sit close to that standard’s specified dimensions. If both results score poorly, your chain is likely worn, stretched or non-calibrated — measure a different section, or contact our team for identification. Never run chain on a gypsy machined for a different standard, even when the size looks similar.
DIN766 — 10 mm
STRONG MATCHCalibrated short link, pitch 28 mm. Compatible with Muir gypsies stamped DIN766-10.
Distance Score 0.42
ISO4565 — 10 mm
CHECK PITCHClose on diameter, further on pitch — verify measurement C before selecting this standard.
Distance Score 2.10
COMMON QUESTIONS
Chain Selection Guide FAQs
Which measurements matter most?
Wire diameter (D) determines the nominal chain size, while pitch (C) is what separates standards like DIN766 from ISO4565. Enter D plus at least one other dimension for a reliable match.
My chain matches two standards — which is correct?
Start with the lower Distance Score in the chain selection guide results, then verify against the stamp on your gypsy or your windlass manual. If the scores are close, the chain may be worn — have it inspected before reusing it.
What size chain does my boat need?
This chain selection guide identifies existing chain. To size new chain, see our anchor chain size guide for a chart matching vessel length and displacement to diameters from 6mm to 16mm.
KEEP GOING
Related Anchoring Resources
Still unsure of your match?
Our engineers can identify chain from your measurements and confirm gypsy compatibility across the full Muir range — recreational to mega.
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