ISO 4565 Anchor Chains: G43 vs G60 vs G70 – What’s the Difference?
- Shake Sure
- Aug 27
- 3 min read
Updated: Sep 4
When it comes to choosing the right ISO 4565 chain for your boat, the grade makes a big difference. Three of the most common types—G43 anchor chain, G60 stainless steel chain, and G70 marine chain—each offer unique advantages in strength, durability, and corrosion resistance. Selecting the right grade isn’t just about price; it’s about matching the chain to your vessel, windlass, and the conditions you sail in.
In this guide, we break down the key differences between G43, G60, and G70 anchor chains under ISO 4565 standards to help you make the best choice.
Strength: Load Ratings That Matter
When you’re out on the water, your anchor chain isn’t just a piece of gear—it’s your lifeline. The last thing you want is to second-guess whether your chain can actually hold when the wind picks up or the current shifts. That’s why understanding the load ratings behind each grade matters. Let’s break it down.
A solid choice for small to mid-size recreational boats. With a high tensile anchor chain rating and a safe working load around 2,450 kg (for 10 mm links), it’s dependable for everyday anchoring.
Designed for serious strength, the G60 offers a safe working load up to 2,800 kg. Built from AISI 316 stainless steel, this chain is proof that performance and appearance can go hand in hand.
With a minimum break load of 3,000 kg (10 mm links), the G70 marine chain is the workhorse for larger vessels. It’s the strongest per weight, making it ideal when you want power without excess bulk.
Durability: Built for the Long Haul
Chains take a beating. From constant tension on the windlass to grinding over the bow roller, durability is what separates a chain that lasts a few seasons from one that you can really trust for the long run. Here’s how each grade holds up over time.
G43: Made from carbon steel and often supplied as a hot dip galvanised anchor chain, it delivers solid performance at a fair price. Perfect for general use, though it may require more upkeep over time.
G60: As a stainless steel anchor chain, this grade excels in fatigue resistance and maintains a polished look even in harsh saltwater conditions. The smooth finish means less wear on your boat windlass chain and less maintenance overall.
G70: Heat-treated and galvanised, this chain provides exceptional strength-to-weight ratio. However, it can be trickier to re-galvanise, so you’ll want to stay ahead on inspections.
Corrosion Resistance: Staying Strong in Saltwater
If you’ve spent any time around boats, you know saltwater is relentless—it finds its way into every link, every crevice, and it doesn’t take long before rust shows up. Choosing the right chain is about picking one that won’t give in when corrosion starts its attack.
G43: Offers solid corrosion resistance with hot-dip galvanisation. Like G70, it typically lasts 5–7 years before the zinc layer wears down and re-galvanising is needed.
G60: The most corrosion-resistant of the three. The stainless steel finish prevents rust, staining, and galvanic corrosion—even in warm, high-salinity marinas.
G70: Corrosion resistance is the same as G43, with a lifespan of about 5–7 years before re-galvanisation is required. However, G70 delivers higher strength and comes at a higher cost than G43.
Best Use Cases: Which Chain Fits Your Vessel?
G43 Anchor Chain – Budget-friendly, versatile, and great for small boats. Use as your primary or backup chain when moderate corrosion resistance is acceptable.
G60 Stainless Steel Chain – Premium boats, stainless steel windlasses, and warm-water sailing. Ideal when aesthetics, performance, and corrosion resistance are top priorities.
G70 Marine Chain – Large boats, offshore mooring, and commercial vessels. Perfect when you need maximum strength without adding unnecessary weight.
Final Thoughts
Choosing between G43, G60 stainless steel, and G70 marine chains can feel complicated—do you prioritise cost, corrosion resistance, or maximum strength? For most small boats, G43 is more than reliable. For premium boats, G60 stainless steel anchor chain balances performance with style. And for heavy-duty marine use, G70 delivers unmatched tensile power.
But here’s the thing—you don’t have to figure it all out alone. At Shakesure, we make the choice simple. We stock ISO 4565 chains in G43, G60, and G70, and we’ll guide you to the best option for your vessel. No worry, no hassle—just the right chain for the job.
Explore our full range of marine mooring chains today and anchor with confidence.
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