Chain - High Test 40/43

What Is High Test 40/43 Chain?

High Test chain — commonly referred to as Grade 40, Grade 43, HT, or G4 chain — represents the modern standard in marine anchoring. High Test (HT) chain is made from high-tensile carbon steel links that are also heat treated, setting it apart from older-generation options like BBB or proof coil chain. The name "High Test" itself comes from the chain's ability to test higher in strength than its predecessors, and you'll often see the terms High Test, High Tensile, and Heat Treated used interchangeably in the marine world.

Why High Test Chain Matters for Anchoring

The most compelling reason boaters upgrade to Grade 40/43 chain is the dramatic improvement in the strength-to-weight ratio. Grade 43 chain delivers approximately twice the working load limit of BBB or proof coil chain of comparable link size — meaning you can achieve the same holding power with a lighter, more manageable rode. For cruising sailors and powerboaters alike, that weight savings at the bow can meaningfully reduce pitching in a seaway and improve overall trim, especially on lighter displacement vessels.

High Test chain's short-link ISO design also makes it exceptionally well-suited for windlass operation. The calibrated link geometry fits the wildcat (gypsy) of most windlasses marked with an "HT" designation, and the shorter, more flexible links are less likely to tangle in the chain locker during retrieval. If you're running an electric or hydraulic windlass, confirming compatibility with your windlass manufacturer before purchasing is always a smart step.

Key Features to Look For

• Hot-dip galvanizing: A quality hot-dip galvanized finish provides far superior corrosion resistance compared to mechanical or electroplated coatings — critical for chain that spends its life submerged in saltwater.
• ISO short-link compliance: Ensures proper fit with windlass wildcats and smooth operation through the chain locker.
• Working load limit (WLL): Match the chain's WLL to the size and displacement of your vessel and the conditions in which you anchor.
• Domestic manufacturing: U.S.-made chain is produced to consistent metallurgical standards and is traceable to specific quality benchmarks.
• Link diameter and length: Common sizes run from 1/4" through 1/2", with 5/16" and 3/8" being the most popular choices for recreational and coastal cruising.

Choosing the Right Size

Selecting the correct chain diameter comes down to your boat's displacement, the scope you plan to deploy, and bottom conditions in your cruising area. Abrasive bottoms with rock or coral demand a heavier, more wear-resistant chain, while soft-bottom anchorages are more forgiving. A standard all-chain rode for a cruising yacht often runs 200–300 feet, and the catenary (sag) created by that weight keeps the load on the anchor as horizontal as possible — helping the anchor set and hold securely.

Top Brands in High Test 40/43 Chain

Acco Peerless Chain is the benchmark name in domestic marine chain. Established in 1901, the company has built its reputation on high-strength chains used across marine, industrial, and agricultural sectors. Their Grade 43 ISO High Test chain is manufactured in the USA from high-carbon steel, shot-peened before hot-dip galvanizing for enhanced corrosion resistance, and factory-tested to rigorous quality standards — making it a trusted choice for serious cruisers and offshore boaters.