Hardware Chains: what Claude and GPT would buy

Two AI models chose on their own, with no web access. Nobody tested these products: this is what each one says, and how to check it.

Claude and GPT choose the same brand, Campbell, but not the same product

In Industrial & Scientific, Claude and GPT choose the same brand in 52 of 107 categories.

Claude Opus 5.5 · October 28, 2026

Campbell Proof Coil Chain (Grade 30) (line)

Campbell's Grade 30 proof coil is a widely stocked general-purpose hardware chain with a stated working load limit and grade marking, which most light-duty and decorative chains lack.

Not for: Anyone lifting loads overhead, who needs Grade 80 or Grade 100 alloy chain with matching rated fittings, or anyone who only needs a decorative or pull chain.

GPT 6.1 Sol · November 10, 2026

Campbell Grade 70 Transport Chain (line)

A strong, practical choice for heavy-duty cargo securement, with grade markings that help verify suitability for transport applications.

Not for: Overhead lifting or applications requiring stainless steel corrosion resistance.

Which one fits you

outdoor or marine exposure

Campbell Stainless Steel Chain (line)

Stainless chain avoids the rust staining and coating wear of zinc-plated steel in wet locations.

Not for: Buyers who need the higher strength of graded carbon or alloy chain at the same size.

Check before you buy

Rated vs. unrated. Only use chain with a stated working load limit (WLL) for anything carrying weight. Ball, bead, loop, twist-link and sash chains are generally unrated. Decorative and light-duty chains can open at the weld or wire bend under loads far below what their size suggests.
Grade for lifting. Overhead lifting requires alloy chain of Grade 80 or higher with matching rated fittings. Grade 30 proof coil and Grade 70 transport chain are not for overhead lifting. This is the standard rigging rule. Lower grades are for tie-down, barriers and general use.
Finish for environment. Use zinc-plated chain indoors, hot-dip galvanized or stainless outdoors, and 316 stainless for salt water. Bright zinc plating rusts quickly outdoors and stains surfaces.
Fitting compatibility. Size quick links, S-hooks and snaps to the chain's trade size and inner link width, and rate them at least equal to the chain. A system is only as strong as its weakest fitting, and oversized hooks will not seat in small links.

Where to find Campbell Proof Coil Chain (Grade 30)

Walmart
Acme Tools
Industrial Hardware

Shops seen in search results on November 6, 2026. A shop missing here may sell it too. Nothing was checked by a person.

Brands that matter

Campbell: Broad line of proof coil, machine, loop and stainless chain, sold through hardware channels.
National Hardware: Common hardware-store packaged and by-the-foot light-duty chains.
Koch Industries: Hardware chain supplier offering many light-duty and coil chain styles.
Peerless: Known for graded transport and alloy chain rather than decorative styles.

What to avoid

Using any unrated decorative chain to hang heavy fixtures, swings or loads over people
Mixing a rated chain with unrated hardware-store S-hooks
Bright zinc-plated chain for permanent outdoor use

Questions

Can I use proof coil chain to lift an engine or hoist?

No. Overhead lifting calls for Grade 80 or higher alloy chain with rated fittings.

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