Crypto Wallet Backup - Washers Stamping Jig

Paper backups fail. Ink fades. Hardware wallets break.
This 3mm stamping jig is designed to help you create a durable, offline backup of a 12–24 word crypto seed phrase (or any critical secret) by stamping directly into stainless steel washers.

This project was built to be a DIY alternative to expensive commercial metal backups (often sold for hundreds of dollars), while still delivering precision, repeatability, and long-term durability.

How It Works

Each washer is stamped using a guided layout:

• Index markers at the top identify the word position (1–24)
• Up to 8 characters at the bottom store the word itself
  • For BIP-39 wallets, only the first 4 letters of each word are required, making this system compact and efficient

The jig ensures:

• Maintain proper alignment, even for re-hammers.
• Consistent spacing
• More professional results

Key Features

• Designed for 3mm (1/8") metal stamping sets
• Supports washer-based backups (easy to store, reorder, and transport)
• Clear index digits for phrase ordering
• Compact character layout optimized for BIP-39 seed phrases
• Works with standard hardware store parts
• Fully offline, no electronics, no firmware, no trust required

Why Washers?

• Stainless steel is fireproof, waterproof, corrosion-resistant
• Washers are inexpensive, widely available, and easy to replace
• Individual pieces reduce single-point-of-failure risks
• Can be stored on a single bolt or split into multiple locations

Printing Recommendations

Tested successfully with:

• Printer: Bambu P1S
• Layer Height: 0.2mm (Strength preset)
• Walls / Top / Bottom: 4 layers
• Infill: Gyroid, 25%
• Top Layer Ironing: Enabled (purely cosmetic, optional)

Materials Needed

• 3mm (1/8") Letter & Number Metal Stamping Set (6mm characters recommended)
  • Tested with: Owden 36-piece Number & Letter Stamping Set
• 14× Stainless Steel Washers
  • 5/16" or 3/8"
• 1× Bolt
  • 5/16" or 3/8", ~1.5"-2" length
• 1× Matching Nut

Stamping Set (not affiliate links):

Owden: https://www.owdencraft.com/products/number-and-uppercase-letter-metal-stamps-1-8
Amazon CA: https://a.co/d/1rVAyzt
Amazon US: https://a.co/d/2UPT4re

Disclaimer

This jig is a tool, not a security guarantee. Always verify your stamped backup, test recovery procedures, and follow best practices for physical security and redundancy. Never take or post pictures of your backup.