Backups
Frequently Asked Questions about Metal Seed Backups
Why a metal seed backup — isn't paper enough?
An average house fire reaches around 600 °C, with flashover briefly exceeding 1000 °C — paper is long gone by then. Stainless steel only melts at about 1400 °C and titanium at around 1670 °C: both survive a house fire with a wide margin, along with water and corrosion. A metal backup replaces the paper slip as the long-term safeguard for your recovery words — not the hardware wallet itself.
Stamping, engraving or letter tiles — which system should I choose?
Jameson Lopp's stress tests (heat, acid, a 20-ton press) show a clear pattern: solid single plates with deeply stamped characters perform most consistently — the fewer parts, the fewer failure points. In our range that means the stamping systems from Stamp Seed and SEEDOR and the Cryptotag titanium plates. Tile and capsule systems like the Cryptosteel Capsule are more convenient to fill and need no tools at all — and they have passed fire tests up to 1400 °C too. Robustness favors the plate, convenience favors the capsule.
Stainless steel or titanium — does it matter?
For the house-fire scenario both are sufficient: stainless steel (SEEDOR uses grade 316L) melts at about 1400 °C, titanium (Cryptotag Zeus, Loki and Thor, Stamp Seed) at around 1670 °C while also being lighter and even more corrosion-resistant. What matters more than the material is the construction — deeply stamped characters in a solid plate stay readable even when the surface is discolored. Blocktrainer tested the SEEDOR Safe for an hour at over 1350 °C: tarnished, but the seed remained legible.
Are the first four letters of each word really enough?
Yes. The BIP39 word list with its 2048 words is deliberately built so that the first four letters identify each word uniquely — no two words share the same beginning. That's why systems like the Cryptosteel Capsule or the Trezor Keep Metal provide only four characters per word; during recovery your wallet software completes the full word automatically. This does not reduce the security of your seed in any way. If you prefer, you can still stamp full words — the larger plates have room for it.
How do I transfer my seed onto the metal safely?
Read the words only from the display of your hardware wallet and put them straight into the metal — never photograph them, type them out or park them in a cloud note. Stamping kits include a guide that fixes plate and letter punches in place; practice on a spare piece first, because a stamped character cannot be removed. Afterwards check every word against the BIP39 list and verify the backup with your wallet's recovery check (dry run) before trusting it with larger amounts.
How many copies do I need — and where should I store them?
The proven approach is at least two complete copies in physically separate locations — for example at home plus a bank deposit box — and always separate from the hardware wallet, so a single burglary can't capture both. Keep in mind: whoever finds the plaintext plate can access the coins unless a passphrase is set, so the storage location is part of your security. We advise against the "clever" idea of splitting one seed across two half-backups — it lowers security and doubles the risk of loss at the same time. An optional BIP39 passphrase belongs on its own separately stored backup, never on the same plate.
How is a metal plate different from NFC cards like the Satodime?
A metal plate stores the seed in plaintext — but with no electronics, no expiry date, and fire and water resistance. NFC backup cards store the seed encrypted and PIN-protected in a secure element chip; in return they are electronics with a limited lifespan and are not built for fire. A special case is the Satochip Satodime: it is not a seed backup but a bearer card — the private key is created inside the card's chip and only revealed when it is unsealed once. That makes it a way to physically hand over or gift sats; backing up your wallet remains the job of the metal plate.