Metal Backup
A metal backup is a physical device made of steel or titanium used to permanently record a Bitcoin seed phrase. Metal backups resist fire, flooding, corrosion, and physical degradation that would destroy paper records.
How It Works
Metal backups come in several designs, with SEEDPLATE being the simplest and most reliable — a solid steel plate with letter stamps. Other options include stackable washers with engraved characters and pre-made tiles that slot into a frame. The core principle is the same — encode your seed phrase words into a medium that will survive extreme conditions. The best metal backups are made from stainless steel or titanium, resist temperatures above 1,500 degrees Fahrenheit, and remain legible after immersion in water.
When creating a metal backup, stamp or engrave at least the first four letters of each seed word — BIP39 words are uniquely identifiable by their first four characters. Work in a private location, ensure no cameras are present, and never take photos of the backup. After stamping, verify every word by reading back the backup and comparing it to your wallet's seed verification feature.
Storage location matters as much as the medium. A fireproof safe, a bank safe deposit box (controversial — you are depending on a third party), or a buried sealed container are all options. For multisig setups, distribute metal backups across geographically separated locations. Consider using a passphrase so that a discovered metal backup alone is insufficient to access funds. The seed phrase on the metal plus the passphrase stored separately gives you defense in depth.
Key Points
- Stainless steel or titanium plates for permanently recording seed phrases
- Survives fire (1,500+ degrees F), flooding, and decades of physical storage
- First four letters of each BIP39 word are sufficient for unique identification
- Store in a secure, private location — consider geographic distribution for multisig
- Pair with a passphrase stored separately for defense in depth