Grade 70 vs Grade 80 Chain for Cargo Securement

Quick Answer

Grade 70 is the federal minimum for cargo securement chain. Grade 80 offers higher WLL at the same diameter, which matters when load weight or attachment size limits adding more chain. Use manufacturer or carrier-approved WLL tables — not this comparison — for live planning.

The practical difference

At the same diameter, Grade 80 chain carries a higher WLL than Grade 70. That margin is modest at larger diameters and more significant at smaller ones. Where Grade 80 matters most is when the attachment point — hook, ring, or anchor — is sized for a smaller chain but the load needs more WLL.

For most general flatbed freight, Grade 70 transport chain in appropriate sizes meets the federal standard. Grade 80 becomes the practical choice when load WLL requirements push against what Grade 70 can deliver at the anchor-compatible chain size.

Condition outranks grade

A serviceable Grade 70 chain with readable markings and confirmed WLL is more reliable than a Grade 80 chain with cracked links, missing markings, or an unknown service history. Grade sets the ceiling; condition determines whether the chain gets credited at all.

Grade 70 and Grade 80 chains of the same diameter look similar without the link markings. Never assume grade from appearance. Read the marks on the links.

What the grade numbers mean

Chain grade is a shorthand for minimum breaking strength relative to chain diameter. Grade 70 chain (transport chain) must meet a breaking strength of 70,000 psi of tensile stress — that's the origin of the number, not a WLL value. Grade 80 lifts that requirement to 80,000 psi, and Grade 100 to 100,000 psi.

In practical terms, a Grade 80 chain in a given diameter has a higher rated WLL than a Grade 70 chain of the same diameter. The same WLL can be achieved with smaller-diameter Grade 80 chain than Grade 70 chain — which matters when weight, bulk, or hook attachment size is a constraint.

Grade identification on links: Grade 70 is typically marked '7' or '70' or 'G7.' Grade 80 is typically marked '8,' '80,' or 'G8.' These marks appear on the links themselves, not just on the package. Always verify markings on actual links before crediting a chain in a securement plan.

WLL differences at common chain sizes

At 3/8-inch diameter, Grade 70 transport chain is commonly rated around 6,600 lb WLL. Grade 80 alloy chain at the same diameter is typically rated around 7,100 lb WLL — about 8 percent more capacity. At 1/2-inch diameter, the difference is larger: Grade 70 around 11,300 lb WLL versus Grade 80 around 12,000 lb.

These figures are examples only — actual WLL depends on the specific manufacturer and the standard the chain was produced under. Use manufacturer data, carrier-approved WLL tables, or the marked tag on the chain assembly for live planning. Do not use this comparison page as a WLL reference.

Where Grade 80 shows a more meaningful difference is at smaller diameters. A 5/16-inch Grade 80 chain can approach or match the WLL of a larger Grade 70 chain, which matters for attachment points where hook or link size is limited by the anchor fitting.

When Grade 80 makes sense on a flatbed

Most flatbed securement in general freight uses Grade 70 transport chain and meets the federal standard. Grade 80 becomes relevant when: the aggregate WLL requirement for the load is high and adding more chains isn't practical; the attachment hardware (hooks, rings, anchors) is size-limited in a way that makes larger Grade 70 chain a poor fit; or carrier policy specifies Grade 80 for specific commodities like metal coils, machinery, or vehicles.

Grade 80 alloy chain is also the starting point for lifting sling applications under different standards — but that's a separate context. For cargo securement under 49 CFR Part 393 Subpart I, the question is whether the chain's WLL and condition meet the requirements for the load. Grade 80 often does, but so does properly sized Grade 70.

What 49 CFR 393.110 requires

49 CFR 393.110 sets the federal chain requirement for cargo securement. It references ASTM A906/A906M — the specification for Grade 70 transport chain — as the minimum standard for chains used as tiedowns on CMVs. Grade 80 and Grade 100 chains exceed that minimum.

The rule doesn't mandate Grade 80 for most cargo. What it does mandate is that chains used as tiedowns meet or exceed the Grade 70 transport chain specification and that the WLL of the tiedown assembly meets the securement requirements for the cargo. Whether that means Grade 70, Grade 80, or higher depends on the load and the calculation.

For commodity-specific sections (metal coils at §393.120, heavy vehicles at §393.130, etc.), check whether that section specifies chain type or grade. Some sections add requirements that go beyond the general minimum.

Condition matters more than grade

A Grade 80 chain with a cracked link, deep corrosion, or illegible markings is worse than a serviceable Grade 70 chain with known markings and a confirmed WLL. Grade is a starting point for planning — condition is what determines whether the chain can be credited at all.

If you're evaluating a chain and the marking is worn, missing, or inconsistent with the chain's apparent construction, pull it from service until the grade and WLL can be verified. Do not assume grade from appearance alone — Grade 70 and Grade 80 chains of the same diameter can look similar and are not visually distinguishable without the link markings.

The assembly WLL is always controlled by the lowest-rated component: chain, hook, binder, and anchor point. A Grade 80 chain with a Grade 70 hook operates at Grade 70 capacity.

Practical Notes

Treat this page as a planning reference. Verify the current regulation, carrier policy, shipper instructions, manufacturer ratings, and equipment condition before a truck moves.