Update – March 12th, 2025:
Hello crypto bros! What a cringe alt season we had this cycle, am I right? Time to stash all our gains in a vault and wait for the next bull run, huh?

Anyway, I wanted to update all the wishlisters: I can no longer sell on Tindie. Their cut is absurdly high, and I can only withdraw USD, after which PayPal takes another cut to convert it to euros. Add inflation to the mix, and I was literally losing money on this.

If you’re still interested in getting one, contact me. However, you won’t have the same customer protection as you did with Tindie: you’ll just have to trust me.

Take care, everyone! And remember: NEVER share your seed phrase!

What is it?

This is a cheap DIY metal seed phrase/recovery backup. When setting up a non-custodial crypto wallet, you'll be prompted to securely back up a series of words, typically 24. This 'recovery seed' allows you to recover your funds even if your wallet is physically destroyed. You'll typically be asked to write down your recovery phrase on a piece of paper; however, paper isn't ideal for long-term storage. This is why metal seed backups exist. They protect your recovery phrase from fire, flood, and other disasters.

Why did you make it?

This year was absolutely crazy for cryptocurrency, and if you're reading this, there's a good chance you're looking for a solution to secure your recovery seed without spending all your money on an overpriced steel wallet. You’ve probably already seen those, they can cost up to 249€. This is just ridiculous.

One day I came across this website created by Jameson Lopp, where he tested the most popular metal seed storage solutions.

It turns out that the most expensive options weren’t always the most robust. I was quite surprised to see the highly popular Cryptosteel fail the tests.

The SAFU Ninja surprised me the most. It was a DIY solution that outperformed many commercial steel backups at a fraction of the cost.

Additionally, this handy little jig can help you align the punches to ensure your seed is both readable and neatly presented.

There’s also this incredibly talented individual who machined a capsule using his metal lathe for his version of the SAFU Ninja.

However, not everyone has a metal workshop in their garage or easy access to a 3D printer...

That’s exactly why I’ve put together this kit!

What makes it special?

It's a fraction of the cost of all commercially available products. Seriously.

IMPORTANT

You’ll need some tools that aren’t included (they’re incredibly heavy, and the shipping costs alone exceed the price of the product itself).

Tools needed:

• Punch set with 3mm letter height: The width of the punches must be exactly 6mm; otherwise, they won’t work with the jig. I recommend using this set from Amazon (it’s the one I used, and it’s reasonably priced).
• A thumb detector (a hammer): There’s a good chance you already have one at home.
• An anvil: You don’t need a blacksmith-grade anvil, a jewelry anvil works perfectly. Alternatively, any other hard, flat surface should do the job.
• Some tape
• A 3mm Allen/hexagonal key wrench for the bolt: If you’ve bought IKEA furniture before, you likely already have one lying around.
• An 8mm wrench

What is included?

• 1 stainless steel (304) capsule
• 24 M5 stainless steel (304) washers: Includes 2 extra washers, one for practicing your swing skills and another as a spare in case of a mishap.
• 1 M5x35mm flat-head Allen/hexagonal socket stainless steel (304) screw
• 1 M5 stainless steel (304) cap nut
• 2 spare O-rings

Optional

• Optional 3D-printed jig: I can include a 3D-printed jig upon request—just make sure to select the option when placing your order.
• 2 tamper-proof stickers: These allow you to check if someone has attempted to access your seed.

Tips

• Avoid excessive force when stamping the washer: Using too much force can result in a warped washer.

• Thin letters/numbers (e.g., L, I, J, T, 1, 7) require less pressure: These characters need less force to leave a clean impression. For example, if you use the same amount of force for both "H" and "L," you’ll notice that "L" will be stamped deeper than "H." Use the extra included washer to practice your technique.

• Use masking tape under the washer: This helps keep the washer in place while stamping.

• The dreaded "D": I always seem to stamp the "D" backwards, no matter what (T_T). Maybe you’ll succeed where I failed!