Lockout & Tagout Products: 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 product: Master Lock 410

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

Claude Opus 5.5 · October 28, 2026

Master Lock Zenex 410

The Zenex 410 is a lightweight, non-conductive thermoplastic safety padlock with a dedicated key, which is the core of any lockout program and the item teams most often run short of.

Not for: Sites with outdoor, high-heat or corrosive points that need a sturdier metal-bodied safety padlock, and anyone who needs a full kit with hasps and tags rather than just locks.

GPT 6.1 Sol · November 10, 2026

Master Lock 410

Durable thermoplastic safety padlock with key retention, designed specifically for lockout/tagout rather than general security.

Not for: Complete lockout coverage without equipment-specific isolation devices and procedures.

Which one fits you

complete starter set for a shop

Brady (brand)

Brady sells packaged lockout kits that bundle locks, hasps, devices and tags in one container.

Not for: Teams that already own locks and only need specific breaker or valve devices.

tags and tag attachments

Accuform (brand)

Accuform makes a broad range of standardized danger and do-not-operate lockout tags.

Not for: Anyone expecting a tag to replace a lock where the equipment can be locked out.

Check before you buy

One key per lock. Each worker's lock must be keyed differently, and the worker keeps the only regularly used key. Lockout only protects you if nobody else can remove your lock.
Dedicated and identifiable. Under OSHA 29 CFR 1910.147, lockout devices must be used only for energy control and must be standardized by color, shape or size and identify the user. Mixing lockout locks with general-purpose locks defeats recognition and control.
Device fits the energy source. Match each device to the actual breaker style, valve type and size, or plug. A device that does not physically block the isolator is not a lockout.
Group lockout capacity. Use hasps or group lock boxes so every worker on the job can apply a personal lock. Equipment must stay isolated until the last worker removes their lock.
Non-conductive bodies for electrical work. Prefer thermoplastic or nylon padlocks and devices near live electrical equipment. This reduces shock and arc risk while you apply and remove locks.

Where to find Master Lock Zenex 410

Master Lock
Mega Depot
Bayshore Safety

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

Master Lock: The best-known maker of safety padlocks, hasps and lockout devices.
Brady: Broad lockout range that is strong on kits, tags and breaker and valve devices.
Panduit: Electrical-focused lockout devices and safety padlocks.
Accuform: Tags, labels and lockout accessories.

What to avoid

Using ordinary hardware-store padlocks or locks shared with toolboxes and lockers.
Keyed-alike sets handed out across different workers.
Unbranded devices with no fit chart for breakers or valves.
Buying hardware without a written energy control procedure for each machine.

Questions

Is lockout the same as tagout?

No. A lock physically prevents re-energizing, while a tag only warns. OSHA requires lockout when the equipment can accept a lock, and allows tagout alone only with measures that give equivalent protection.

Can a supervisor keep a master key?

Many programs allow a controlled master key or a documented lock-removal procedure, but each worker still needs a personal lock that only they normally remove.

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