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Metal Crypto Seed Backup Plates Compared
Blockplate is the best metal seed backup for most Bitcoin and hardware-wallet users because its punch-grid design has no loose letter tiles, works with 12- or 24-word BIP39 phrases, and records only the first four letters required to identify each word. A center punch and careful setup are required, but the finished plate is simple, compact, and resistant to fire, water, and crushing.
Cryptosteel Capsule Solo is the premium option when tool-free assembly and a cylindrical form are worth the higher price. Trezor Keep Metal is the most polished choice for Trezor owners, while Billfodl suits users who prefer sliding letter tiles. Keystone Tablet Plus is widely available and easy to lock with tamper-evident features, but its moving parts and assembly time make a punched plate more reassuring for long storage.
No metal device protects a seed from a person who finds and reads it. Steel improves physical durability; separate locations, passphrases, multisignature, access control, and tested inheritance protect against theft and single-point failure — see our multisig setup guide for how to remove any single copy as a point of failure in the first place.
| Backup | Format | Material | Setup | Best use |
|---|---|---|---|---|
| Blockplate | Letter-position punch grid | Stainless steel | Center punch | Best overall simplicity |
| Cryptosteel Capsule Solo | Character tiles on a central rod | AISI 303/304 stainless steel | Tool-free tile assembly | Premium compact backup |
| Trezor Keep Metal 24-word | Letter-position marking system | AISI 304 stainless steel | Included marking tool/system | Trezor ecosystem and guided setup |
| Billfodl | Sliding engraved letter tiles | 316 marine-grade stainless steel | Tile assembly | Readable, reusable cassette |
| Keystone Tablet Plus | Sliding letter tiles in a clamshell | Stainless steel | Tile assembly and screws | Familiar wallet bundle option |
| Punchplate 24-Word | Double-sided punch grid | 304 stainless steel | Center punch sold separately | Budget plate |
Our pick: editor's-pick
What a seed backup must survive
A hardware wallet stores signing keys in a device; the recovery phrase recreates those keys if the wallet is lost, damaged, or obsolete. Anyone who obtains the phrase can usually move the funds without the device or PIN. A backup must therefore remain legible after heat, water, corrosion, impact, and decades of neglect while staying secret.
Paper is inexpensive and easy to verify, but it burns, absorbs water, fades, tears, and attracts mold. Laminating can trap moisture or melt. A metal backup is not indestructible—extreme fire can warp it, saltwater attacks some alloys, and demolition equipment can destroy anything—but stainless steel materially improves survival.
Product temperature claims are not comparable laboratory certifications unless the same test protocol, duration, cooling method, and legibility standard were used. A house fire can combine heat, falling debris, water, and corrosion. Favor deep punches or engraved steel over surface ink and avoid designs whose data vanishes when one hinge or fastener fails.
Best overall: Blockplate
Blockplate encodes each recovery word by punching marks into an alphabet grid. BIP39’s 2,048-word list is designed so the first four letters uniquely identify each word. For a word with three letters, record all three. The plate avoids spelling entire words and contains no removable tiles.
The package and model options have changed over time, so check whether the selected plate supports 12, 18, or 24 words and whether a spring-loaded center punch is included. The marking process is permanent. Work slowly, cover all other seed words, and verify each position before striking.
Pros: few failure points, deep permanent marks, compact storage, and no letter inventory to lose. Cons: errors are difficult to correct, the grid is not instantly readable, a punch is needed, and stamping sounds can reveal that sensitive work is taking place.
Best premium capsule: Cryptosteel Capsule Solo
Cryptosteel Capsule uses engraved character tiles threaded onto a stainless-steel core and enclosed by a capsule. The manufacturer says the Capsule uses AISI 304 and 303 stainless steel and withstands temperatures up to 1,400°C/2,500°F. Its supplied tile set can store BIP39 phrases using four-letter abbreviations and other short secrets.
Assembly requires privacy and concentration. Sort the needed tiles, load characters in the correct order, add separators as instructed, lock the stack, and reconstruct the phrase before storage. Loose tiles are an exposure during setup, and a dropped work surface can create a frustrating puzzle. Once closed, the cylindrical design is compact and resists bending better than a thin plate.
Pros: no hammering, deeply engraved characters, high published heat resistance, compact form, and support for more than a fixed grid. Cons: high price, many small parts, slower setup, limited character capacity, and possible sequence disruption if incorrectly locked.
Best guided product: Trezor Keep Metal
Trezor sells Keep Metal versions for 12-word, 20-word, and 24-word wallet backups. The 24-word model uses AISI 304 stainless steel with a black surface treatment. It encodes word prefixes through a marking process and includes purpose-designed tools and instructions. Compatibility is not limited to Trezor when the backup standard matches, but confirm BIP39 versus SLIP39 before buying.
The industrial design reduces uncertainty for a first-time user compared with assembling generic stamping supplies. The cylinder is discreet and mechanically sturdy. Price is higher than a simple plate, and a person using a 20-word Trezor Multi-share Backup must buy the correct model rather than assuming a 24-word BIP39 product fits.
Pros: excellent instructions, strong construction, correct products for Trezor’s backup formats, and an integrated marking system. Cons: premium cost, format-specific models, permanent marking mistakes, and less flexibility than a general character capsule.
Best readable cassette: Billfodl
Billfodl uses engraved character tiles that slide into numbered slots in a clamshell cassette. The product is commonly made from 316 marine-grade stainless steel, an alloy with strong corrosion resistance. Users enter the first four letters of each BIP39 word, close the device, and secure it with its fastener.
The open cassette is easy to audit because the characters read like text. It can also be reused if a wallet is intentionally replaced, although reusing an exposed backup can create operational mistakes. Tile designs have more components than stamped plates, and severe deformation could release or reorder them.
Pros: readable without decoding a grid, no punches or hammers, corrosion-resistant alloy, and established availability. Cons: tedious tile sorting, loose pieces during assembly, moving parts, greater bulk than a plate, and a price above do-it-yourself steel.
Best clamshell alternative: Keystone Tablet Plus
Keystone Tablet Plus also uses engraved letters placed in a stainless-steel shell, secured with screws and designed for 12-, 18-, or 24-word BIP39 phrases through four-letter prefixes. Tamper-evident stickers or a padlock hole can reveal casual access, though seals do not stop a determined attacker.
The tablet is often sold alongside Keystone hardware wallets and is easy to understand. Assembly still exposes the full seed in readable form, and screws or tiles are small. A tamper seal can create false confidence because an attacker can photograph the words without leaving obvious damage if storage is accessible.
Pros: readable layout, broad BIP39 compatibility, no hammering, and familiar form. Cons: multiple parts, slow tile installation, possible mechanical failure, and weaker secrecy than its lock features imply.
Best budget choice: Punchplate 24-Word
Punchplate’s current 24-word product is a double-sided 304 stainless-steel plate measuring roughly 4.25 by 2.25 by 0.070 inches. It uses a quadrant marking system to encode each word’s first four letters and includes instructions and a marker; the automatic center punch is sold separately. The listed plate price is around the $30 range before tool and shipping costs, but check current price.
The design is cost-efficient and contains no moving pieces. Its custom quadrant scheme requires keeping instructions or understanding the decode logic. A conventional alphabet grid can be more intuitive for heirs. Test that a second person can decode it using written recovery instructions that do not reveal the storage location.
Pros: low price, thick 304 stainless steel, 24-word capacity, and minimal mechanics. Cons: tool sold separately, permanent user error, less intuitive decoding, and limited independent test history compared with older products.
Stamping washers: cheap and durable, but easy to botch
A do-it-yourself “safu ninja” backup uses stainless-steel washers stamped with numbered word prefixes and threaded onto a bolt. Materials can cost less than commercial devices, and each washer is thick. Use stainless washers, bolt, and nut of a compatible alloy; mixed metals can accelerate galvanic corrosion.
The drawbacks are substantial: hand stamps can bounce, characters can be shallow, sequence numbers can be omitted, and a loose nut can scatter the stack. Secure it with two nuts or wire according to a tested design, wear eye and hearing protection, and practice on spare washers. Do not use power tools while the seed is visible near cameras or connected devices.
BIP39, SLIP39, and wallet compatibility
Ledger, Coldcard, Blockstream Jade, BitBox02 Bitcoin-only edition, and many Trezor configurations use BIP39 phrases of 12, 18, or 24 words. BIP39 words are unique by their first four letters. Trezor’s newer Multi-share Backup uses SLIP39 and can produce 20-word shares; those words and recovery process differ.
Do not force a 20-word SLIP39 share into a product labeled only for 24-word BIP39 phrases without verifying format support. Also decide where the optional BIP39 passphrase is stored. The seed without the passphrase restores a different wallet; losing either component loses access. Never engrave the seed and passphrase on the same plate.
Setup without leaking the seed
- Buy from the manufacturer or an authorized retailer without sharing unnecessary information.
- Set up offline in a private room with phones, cameras, voice assistants, and networked security cameras removed or covered.
- Verify the wallet-generated words against the standard and number them clearly.
- Practice the punch, stamp, or tile mechanism on non-secret sample data.
- Expose one word at a time and encode it.
- Decode the finished metal backup independently and compare all words and order.
- Perform a device recovery check or dry-run feature before depositing a large balance.
- Destroy temporary notes securely only after successful verification.
Never enter the phrase into a website, password manager, cloud document, printer, ordinary computer, or phone photo. A legitimate wallet support agent will never request it.
Storage strategy matters more than alloy
Do not store the hardware wallet and seed plate together; one burglary or fire can take both. Use two geographically separate, physically controlled locations. A home safe should be bolted down and appropriately fire rated. A bank safe-deposit box adds institutional and access risk and is not FDIC-insured; contents can become inaccessible during closure or legal process.
Two complete seed copies double the number of theft targets. For significant Bitcoin, a 2-of-3 multisignature wallet can place one key at home, one in a secure off-site location, and one with a trusted collaborative custody provider or separate controlled site. Each backup should include the wallet configuration information needed to reconstruct addresses, without putting enough keys together to spend.
Inheritance and verification
An heir needs to know that assets exist, which wallet standard is used, where lawful access instructions reside, and whom to contact. They should not receive the live seed prematurely. Use an estate attorney familiar with digital assets, sealed instructions, and a periodic test schedule.
Inspect metal backups annually for corrosion, movement, legibility, and storage compromise without photographing them. Rehearse recovery on a trusted offline device or use the hardware wallet’s built-in recovery-check app. Never type a seed into the normal operating system of an internet-connected computer.
Bottom line
Choose Blockplate for a low-complexity, permanent BIP39 backup; Cryptosteel Capsule for premium tool-free durability; Trezor Keep Metal for guided support across Trezor backup formats; Billfodl for readable 316-steel tile storage; and Punchplate for a capable budget plate. The product should fit the phrase standard, be easy to verify, and have no unnecessary failure points.
Metal solves fire and water better than paper. It does not solve theft, coercion, inheritance, passphrase loss, or setup mistakes. Practice first, decode the finished record, test recovery with a small wallet, and store components so no single person, place, or disaster can take the funds.